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A study of the reaction of 1-bromo-2-oxoapocamphane in base

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A study of the reaction of 1-bromo-2-oxoapocamphane in base

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Content A STUDY OF THE REACTION OF i i 1-BR0M0-2-0X0AP0CAMPHANE IN BASE BY Wendy Wan-Tek Fong nt A Thesis Presented to the FACULTY OF THE GRADUATE SCHOOL UNIVERSITY OF SOUTHERN CALIFORNIA In Partial Fulfillment of the Requirements for the Degree MASTER OF SCIENCE (Chemistry) August 19?0 UMI Number: EP41651 All rights reserved INFORMATION TO ALL USERS The quality of this reproduction is dependent upon the quality of the copy submitted. In the unlikely event that the author did not send a complete manuscript and there are missing pages, these will be noted. Also, if material had to be removed, a note will indicate the deletion. Dissertation Publishing UMI EP41651 Published by ProQuest LLC (2014). Copyright in the Dissertation held by the Author. Microform Edition © ProQuest LLC. All rights reserved. This work is protected against unauthorized copying under Title 17, United States Code ProQuest LLC. 789 East Eisenhower Parkway P.O. Box 1346 Ann Arbor, Ml 48106-1346 U N IV E R S IT Y O F S O U T H E R N C A L IF O R N IA T H E G R A D U A T E S C H O O L U N IV E R S IT Y P A R K L O S A N G E L E S , C A L IF O R N IA 9 0 0 0 7 C Jl\ This thesis, w ritte n by ........We.ncly. . W an-T e k. . Fong........ under the direction of h§.V....Thesis Committee, and approved by a ll its members, has been p re sented to and accepted by the Dean o f The Graduate School, in p a rtia l fu lfillm e n t of the requirements fo r the degree of _ Master of_ _ Science, f.'Tn Dean D a te 1 . 2 7 . . Q.. THESIS COMMITTEE Chairman A STUDY OF THE REACTION OF I I 1-BR0M0-2-0X0AP0CAMPHANE IN BASE BY Wendy Wan-Tek Fong m A Thesis Presented to the FACULTY OF THE GRADUATE SCHOOL UNIVERSITY OF SOUTHERN CALIFORNIA In Partial Fulfillment of the Requirements for the Degree MASTER OF SCIENCE (Chemistry) August 19?0 To My Dear Parents ACKNOWLEDGEMENTS The author wishes to express her deepest appreciation to Professor Kirby V, Scherer, Jr, for his enthusiastic teaching, encouragement and assistance. Without his continual guidance, this work would not have been possible, I would like to acknowledge financial support from the National Science Foundation, TABLE OF CONTENTS Page ACKNOWLEDGEMENTS ................................. iii LIST OF FIGURES .................... v Chapter I. INTRODUCTION ........................... 1 General Favorskii Rearrangement Ring Contraction Toy Deamination of an Amino Alcohol II. SYNTHESIS PLAN . . . . . . . . . 15 III. EXPERIMENTAL . . . . . . . . . 27 IY. DISCUSSION.................... 39 Summary BIBLIOGRAPHY . . . . . . . . . . . . . ^6 APPENDIX 52 LIST OP FIGURES Figure i 1. H nmr spectrum of l-bromo-2-oxoapocamphane 2. nmr spectrum of methyl 5»5“dimethyl- bicyclo[2,l.1} hexane-1-carboxylate. » . 3. ir spectrum of l-bromo-2-oxoapocamphane • 4. ir spectrum of 5» 5•■•8imethylbicyclo- ^2il ;i) hexane-l-carboxylie acid . , 5# ir spectrum of methyl 5f5-dimethyl- bicyclo[2,1.1) hexane-1-carboxylate . . 6, mass spectrum of methyl 5»5~c iimethyl- bicyclo[2.1.1) hexane-1-carboxylate . . Page 53 54 55 56 57 58 v CHAPTER I INTRODUCTION General Interest in the chemistry of small cyclic hydrocarbons in recent years has remained at a high level, with emphasis particularly on the synthesis of bicyclo (2.1,l) hexane and 1 — 3 its derivatives Investigations of the photolysis of diazocamphor, which through a Wolff rearrangement to the intermediate ketene yielded the ring-contracted 1,5,5-tri- methylbicyclo [2.1 .l] hexane-6-carboxylic acid, have been 4-6 made extensively , COOH Also by Wolff rearrangement, photolysis of certain diazo- bicyclo [3,1,l] heptane compounds gave products with the bicyclo[2,1,l) hexyl carbon skeleton.^ hi/ ^ Photosensitized internal cycloaddition reactions of 1,5“ dienes may in certain cases provide synthetic routes to 2 8-12 these compounds. * hJ. 4>xC0 ^ a , sooc <r InO ^ S e n s it iz e r A ring contraction method by the deamination of a bridge head amino alcohol to form bicyclo[2.1,ljhexane derivatives has been exploited recently. J It is the purpose of this study to investigate the ,possibility of ring contraction by means of a Favorskii i f ;type of rearrangement from a bridgehead substituted ibicyclo[2,2.l) heptan-2-one to the highly strained I i ;bicyclo[2.1. lj hexyl product(s). 3 1i Favorskii Rearrangement The Favorskii rearrangement is the skeletal rearrange ment of oi-halo ketones in the presence of nucleophilie hases, such as hydroxides, alkoxides, or amines, to form carboxylic acid salts, esters, or amides, respectively. The first example of a Favorskii rearrangement was reported by Demarcay in 1880. A, E. Favorskii, a Russian chemist, suggested an epoxyether as a reaction intermediate in 1A 1913* While working with Vi Ni Bozhovskii, he established 1 * 5 that cyclic Ol-chloro ketones J can be converted by alkalies into acids containing one less carbon in the ring. Some of the earlier examples are the rearrangement of 0^-chloro- cyclohexanone to give cyclopentane carboxylic acid and o 1 h I ;of 1,3“dibromo-3-methyl-2-butanone , CHgBrCOCBrMeg, in | 4 I alcoholic potassium hydroxide to give ethyl 3-raethyl-2- i jbutenoate, MegCssCHCOgEt, He also attempted the reaction I 16 = ,of 2-chlorocyclopentanone in alcoholic alkali_, which led J to complete resinification with no trace of cyclobutane- carboxylic acid. Favorskii proposed that the rearrangement proceeds by attack of alkoxide ion at the carbonyl carbon, with repulsion of halide ion, to produce an epoxyether inter- 14 mediate , followed by rearrangement to the product. The postulated rearrangement of epoxyether into product, however, is not likely,, since this rearrangement fails to proceed when starting with pure epoxyethers; The idea that the action of base on oL-halo ketones involves abstraction of hydrogen halide, either by loss of halide from a mesomeric enolate anion or by simultaneous 1 7 ^-elimination r» followed by direct rearrangement to a ketene, which then rapidly reacts with the nucleophile to 1 8 give the product, was introduced by G. Richard, R, R* This mechanistic scheme fails to account for the formation of esters of the trialkylacetic type from (tf-bromo-Ot,#.- dialkyl acetones. A ketene cannot he a reasonable precursor in such cases. 19 There are at least two mechanisms ^ by which the form ation of acids or esters from OC^halo ketones on treatment with hydroxide or alkoxide ion can occur. In cases in which the OC' hydrogen atom is absent, the reaction may proceed by attack at the carbonyl group in a manner very similar to the benzilic acid rearrangement. 6 Cf ! o .11 _^>c- OR | Ph o I f C-Ph v 120— C---C — Ph o o I I I -RO— C C-Ph Ph An example of the application of this "semi-benzilic rearrangement" mechanism is the rearrangement of 2-bromo* 20 4,4-dimethylcyclobutanone. H SBi- - C 2^r -C00H When the fit'-hydrogen atom is attached to a bridgehead carbon Q < | atom, as in 1-bromobicyclo[3«3»l] nonan-9-one , or cage- 22 23 like oC-halo ketones * , . it is relatively nonacidic; therefore, rearrangement again proceeds by this quasi- Favorskii mechanistic pathway. o H Br COOK 34% 7 Oti o. COOH B r HOOC Br s The nonacidie property of a bridgehead proton is probably due to the inability of the bridgehead carbanion to be stabilized through its enolate anion, since formation of such an enolate anion would involve a double bond at a Zk bridgehead, in violation of Bredt's rule. H o o Most Favorskii rearrangements are initiated, however, 2 * 5 by abstraction of an oC' proton by base. J It was in 1950 iL, that Loftfield by the rearrangement of C-labeled 2-chlorocyclohexanone demonstrated that the (X^and o£* carbons become equivalent and postulated cyclopropanones as the symmetrical reaction intermediates in Favorskii reactions. OR. ,COOf?3 OOR- 4- R, R2 1 It was found that rearrangement of C-labeled 2-chloro* 27 cyelohexanone 1 leads to a mixture of two products. o : o Cl OK Q c : Cl OR hor COOfc * < h + cooR o It has also been shown that in the presence of base, the loss of hydrogen chloride from l-chloro-l-phenyl-2-propanone i or 3-*chloro-l~phenyl-2-propanone leads to the same product, • p Q suggesting a common intermediate. 9 House and Richey2^ suggested that perhaps there are two possible routes to a cyclopropanone intermediate, It can be visualized as being generated by a concerted 1,3- 30 elimination-' , as shown in the scheme below, ^CH2Cl * > CO' CH, H ch3 p C H CO CH H Cti30 CHjOH co,ch3 or through rearrangement of a dipolar ion intermediate, formed by expulsion of halide ion from the preformed car- banion (Aston-Dewar mechanism-^ ). p| v / R3 CX — CO— CH -2tl. o i i ' 'CX -xr ■> o~ The Loftfield mechanism differs from the Aston-Dewar mechanism in that formation of the cyclopropanone inter mediate is through displacement, rather than through collapse of a dipolar ion, while the concerted 1,3-elimin ation differs from them in that loss of proton and cyclo propane ring formation occur simultaneously. In the case of unsymmetrical 0(-halo ketones, cyclo propane ring cleavage leads to formation of the more stable of the two transient carbanions, it being generally established that the order of stability of unconjugated Til carbanions is tertiary< secondary< primary<benzyl. While considerable effort has been devoted to defining the exact nature of the "symmetrical intermediate^)", the 0 possibility that the semibenzilic mechanism could be operating in the same reactions was often overlooked. A compound with an acidic hydrogen, 2-bromocyclobutanone, :has been found to rearrange by a route not involving a symmetrical intermediate. ^ Nevertheless, there is sub stantial evidence indicating that an Of-halo ketone with an , OC-hydrogen atom can undergo rearrangement either by way of [ a . cyclopropanone intermediate or by way of a semibenzilic intermediate depending on the particular compound and the experimental conditions, 2« Ring Contraction by Deamination of An Amino Alcohol The deamination of amines has provided an abundance of O O molecular rearrangements. The semipinacolic rearrange ment is a reaction of 2-hydroxyamines in the presence of nitrous acid to give aldehydes, In the case of cyclic compounds, ring contractions may be observed; Thus, 2-amino-cycloheptanol when treated with nitrous acid gave 30 ring-contracted aldehyde as the reaction product. The ■only product detected in the deamination of 1-amino-3,3- dimethylbicyclo(2»Z,l] heptan-2-ol was the ring-contracted r 1 k n 1 3 5,5-dimethylbicyclo[2,1,lj hexane-1-carboxaldehyde. * J MH OH cHO The reaction is believed to be initiated by the action of nitrous acid on the primary amine to form a diazonium .j, cation (RNg ), followed by decomposition of the diazonium salt to give an exceptionally reactive carbonium ion. It 12 is likely that the rate of departure of nitrogen is immeasurably fast, because molecular nitrogen is a very stable entity and the driving force for its formation is very high. Nitrogen also bears no charge, and, therefore, there is no or very little charge-charge interaction in the transition state for its departure; The electron pair then approaches the bridgehead carbonium center from the opposite side (back-side attack) to form the ring- 'contracted aldehyde with inversion of configuration at the bridgehead center. The mechanistic scheme^ is indicated ,It is noteworthy that there is no product resulting from 1,2-hydride shift, although such a mechanism would give a ;ketone(I) bearing much less strain than the aldehyde obtained; below. HONO 13 1 Formation of the highly strained aldehyde can be easily explained by the fact that an anti and nearly coplanar relationship exists between the 0g-0^ and C^—N bonds of the diazonium intermediate. In the deamination of the two isomers of 2-amino-4—t-butylcyclohexanol (hydroxy cis and trans to the t-butyl group), again there is this anti relationship between C^—Cg and C^—N bonds, as shown below. Larson and his co-workers^1 also carried out the deamin ation of l-amino-^l—bromo-7»7-dimethylbicyclo [2.2,l) heptan- 2-ol, and found that the yield of 4-bromo-5,5-dir nethyl- bicyclo(2.1,l) hexane-1-carboxaldehyde was approximately 70%, Both the Favorskii rearrangement and the semipinacolic rearrangement lead to ring-contraetion products in cyclic or bicyclic compounds. The former proceeds by a 'more push-less puli' mechanism, whereas the latter proceeds by a 'more pull-less push* mechanistic pathway. t f ° £ r t f r~ OH Favorskii type semipinacolic type CHAPTER II SYNTHESIS PLAN The compound of interest in this study, l-bromo-2-oxo- apocamphane, is synthesized from ketopinic acid, which in turn can he synthesized according to the original procedure l f . O or Bartlett and Knox ± or as described by them in Organic k'S Synthesis. J While the conversion of ketopinic acid to the bromide proceeds in good yield, the preparation of ketopinic acid proved troublesome and considerable time was spent trying to improve the preparation• The starting material, 1O-camphorsulfonic acid(II), is converted by phosphorus pentachloride to 1O-camphorsulfonyl chloride(III) in good yield. CH4saH PCI, II III 16 1O-Camphorsulfonyl chloride is then oxidized in hasic medium to ketopinic acid(V), possibly through an inter mediate sulfene. Ill aq Na^CO^ KMnOi o IV COOH V Sulfenes are now generally accepted as possible inter mediates in reactions under basic conditions of sulfonyl halides bearing oC-hydrogeni For example, reaction of methanesulfonyl chloride with triethylamine in the presence of an enamine or ketene acetal yields products of cyclo- iaddition of the intermediate with the electron-rich ‘ ‘ iZ'w/iM 'Olefin, 17 CH^SOgCl + NEt3 2*” 2 0 * 5 OR Their chemistry has been reviewed, > The Organic Synthesis procedure gives ketopinic acid in only 20-30$ yield from the sulfonyl chloride, presumably owing to competing hydrolysis of the sulfonyl chloride to unreactive sulfonic acid. In view of the low yield, attempts were made to modify the reaction conditions. Ln ko Earlier studies * showed that when camphorsulfonyl chloride was treated with triethylamine or pyridine, 1O-chlorosulfoxide camphor(VI) might be an alternative .pathway to ketopinic acid, 1O-Chlorosulfoxide camphor when I I : oxidized by potassium permanganate in sulfolane (tetra- !hydrothiophene-l,1-dioxide) was found to give a slightly .better yield of ketopinic acid. However, problems in extraction of the product from sulfolane far overshadowed 18 the better product yield obtained by this procedure. The overall oxidation-reduction stoichiometric equation is as follows. + J) + 2 KMnO^ > III + 2 Mn02 + KgSO^ I i j It .was,Wedekind and co-workers who first postulated a I i jreaction mechanism for the formation of 1O-chlorosulfoxide I I hn Icamphor from 1O-camphorsulfonyl chloride. V They observed jthat the camphor skeleton remains unchanged while trans- i 'formation only occurs at the MSHgSOgCl group, and suggested i ithat the reaction proceeds by elimination of hydrogen I chloride from the sulfonyl chloride to form a sulfene, ■which then extracts a molecule of water from another mole- pule of sulfonyl chloride to give 1O-chlorosulfoxide Pamphor(VI) and 10-camphorsulfonic acid. .COOH 19 III III IV C = SO; -Ha » IV CH.SO.H This mechanism is somewhat doubtful because phosphorus ipentoxide fails to eliminate a molecule of water from III, Strating.in 196^ noted that only iO-D-chlorosulfoxide ; camphor could be isolated from the reaction mixture of 10-D-camphorsulfonyl bromide, p-toluenesulfonyl chloride and pyridine, and that the addition of a second, unidentical sulfonyl chloride enhances the yield of the chlorosulfoxide camphor formed. From these two findings, he introduced the following mechanistic scheme for the formation of chlorosulfoxide camphor from its sulfonyl chloride. 20 The compound, 1O-chlorosulfoxide camphor, has strong infrared absorption at 1752»-1150i 1132 and 1052 cm"1- , and shows in the nmr spectrum only the geminal dimethyl, methylene and methine hydrogens. The structure has also h'j been proved chemically. ' I lq King and Durst ^ have also prepared one of this little known class of sulfur compounds. Thiobenzoylchloride-S- oxide, C£H^C(C1)s =S0, can be prepared from the reaction of benzylsulfonyl chloride with triethylaminei 21 SO Et0N I I PhCH2S02Cl 2 > cyclohexane ' Ph-C-Cl Another minor by-product of the Oxidation of I IN’ 10-camphorsulfonyl chloride, conspicuous because of its insolubility and camphor-like fragrance, is 10-chloro- camphor(VII). This compound was identified through its melting point and spectroscopic properties. The compound has infrared absorption at 1739 cm (Ce=0), and a doublet — 1 at 1389 and 137^ cm . The nmr spectrum of this material shows the presence of an AB quartet centered at 3*7 ppm, which indicates that the two hydrogens of the chloromethyl group are magnetically non-equivalent• l©-Chlorocamphor is also obtained when camphene(VIII) is treated with ; hypochlorous acid and the chlorohydrin produced oxidized iwith chromic acid ch^g 1. H0C1 2. CrO- VIII VII 22 There are at least two mechanistic pathways which can account for the formation of 10-chlorocamphor in the oxidation reaction or during the preparation of the sulfonyl chloride. The first probably involves free radical inter mediates; It has been shown that alkanesulfonyl chlorides undergo thermal decomposition to give alkene, sulfur dioxiHt ide, alkyl chloride, and hydrogen chloride;^ W h e n 10-camphorsulfonyl bromide is heated in a vacuum with iron powder, 10-bromocamphor is produced. Therefore, it is only reasonable to view the mechanism of the formation of 10-chlorocamphor to be very much similar. CHjSOjCl o + Cl* III + SO 2 VII An ionic pathway, such as that known in the decom position of chlorosulfites-^, would be a second mechanism. Accordingly, this would involve the internal return of chloride in a manner similar to the S i reaction. However, a carbonium ion of a neopentyl derivative very readily product derived from the neopentyl system in this case would be a bridgehead carbonium ion. It may be noted that participation in neopentyl systems is enhanced if strain In view of the liklihood of rearrangement with an ionic mechanism and the fact that no product actually derived from the rearranged ion was detected, it is unlikely that the second mechanism is a reasonable one for the formation i jof 10-chlorocamphor. The synthesis of l-bromo-2-oxoapocamphane(IX) from ketopinic acid is carried out by the Cristol-Firth modifiea tion of the Hunsdiecker reaction. Stock, Baker and Holtz <4 undergoes rearrangement to give a tertiary cation.-' The relief during rearrangement is possible. 2 i f - observed a mixture of 1-bromo- and l-chloro-bicyclo(2.2,2] octane from the brominative decarboxylation of bicyclo $2S2T2]octane-1-carboxylic acid with bromine and mercuric cn oxide in carbon tetrachloride. COOH + HgO + Br They believed that the reaction involves a bridgehead radical, which reacts with bromine or the solvent to produce the observed products. Recently, Ziebarth^ was successful in preparing bromine oxide from the reaction of bromine with mercuric oxide, and he has also been able to use it for brominative decarboxylation. He, therefore, proposed that the mechanism of the modified Hunsdiecker reaction involves both the bromine oxide as a reaction intermediate and a radical mechanistic pathway, HgO + 2 Br2 --------------^ HgBr^ + Br20 ' Br20 + 2 RCOOH -------------> 2 RCOOBr + HgO i ( RCOOBr ------------- > R* + Br* *A,C0o 1 K 2 R* RCOgBr > RBr + RCOg R* + Br* ----------: > RBr 25 Accordingly, thermodified Hunsdiecker reaction can be written as shown. COOM o V + Br* -t C0Z o + * B r O IX It may be possible for the bridgehead radical to react not only with the bromine radical but with mercuric bromide to give bridgehead alkylmercuric bromide as well, if the postulated reaction sequence holds true. V. Spaziano in fact isolated in low yield a substance with the correct elemental composition for the bridgehead alkylmercuric bromide when the modified Hundsdiecker reaction of ketopinie acid was carried out in ethylene dibromide as solvent. ^ However, it was not observed in this present study. : 26 It has talso been observed that a phenyl radical may react with mercury acetate to displace an acetoxy radical, and one of the reaction products obtained is phenylmercuric acetate,^ C6H5* + (CH3COO)2Hg > GgH^HgOCOCH^ + CH^COg CHAPTER III EXPERIMENTAL All melting points are uncorrected. Gas-liquid parti tion chromatographic (glpc) analyses were carried out on a dual column Hewlett-Packard F & M Scientific model 700, equipped with thermal conductivity detector j and 6' x 4" columns packed with neopentyl glycol succinate (10fo) by Applied Science Laboratories, Inc, on 60-80 mesh Chromosorb WAW, The columns were silanized with dimethyldichloro- silane. Unless otherwise noted, the helium flow rate was about 28 cc per minute, and all analyses were performed with temperature programming using a Hewlett-Packard model 2^0 temperature programmer from an initial temperature of 100°C to hold at 190°C at 10°C per minute. A Perkin-Elmer model kS7 grating infrared spectro photometer was employed for infrared spectra. Nuclear magnetic resonance data were obtained on a Varian A-60 27 analytical nmr spectrometer. Unless otherwise indicated, solvents and reagents were of a commercial reagent quality, and camphor deriva tives were racemic. 1O-Camphorsulfonyl Chloride. J 1O-Camphorsulfonic acid, 116 g (0.05 mole), was placed in a one liter three neck flask equipped with a mechanical stirrer and condenser with calcium chloride drying tube. Phosphorus pentachloride, 120 g (0.57 mole), was added to the reaction flask in one portion while the reaction flask was being cooled in an ice bath. The stirrer was turned by hand slowly to start the reaction by mixing. Soon a vigorous reaction occurred giv ing off a large amount of hydrogen chloride. When the reaction had subsided slightly, the mechanical stirring was started, and the ice bath was removed. The mixture was stirred for four hours at room temperature. Then the excess phosphorus pentachloride was hydrolyzed by pouring the reaction mixture slowly into a large excess of ice- water in a three-liter beaker. Vigorous stirring was necessary both to insure complete hydrolysis of excess phosphorus pentachloride and to prevent localized heating up of water which might hydrolyze the product sulfonyl chloride back to sulfonic acid. The precipitated 10-camphorsulfonyl chloride was quickly separated from the aqueous solution by filtration and was washed several times with chilled water. The yield of crude white crystals was 82.4 g (66% yield). This product was used immediately in the oxidation reaction without any further purification. Oxidation of 10-Camphorsulfonyl Chloride. J Anhydrous sodium carbonate, 115 g (1*08 moles), was dissolved with mechanical stirring in 900 ml of water in a four liter beaker heated on a steam bath. A boiling solution of 115 g (0.73 mole) of potassium permanganate in 600 ml of water was prepared on a hot plate. About one-third of the hot •permanganate solution was added to the hot sodium carbonate solution. This was followed by about one-third of the :10-camphorsulfonyl chloride prepared above. After about five minutes, an additional 200 ml of hot potassium per manganate solution was added and again followed by another ; : j 'one-third portion of the sulfonyl chloride. After a similar, i j i interval, the remainder of permanganate solution and the remainder of sulfonyl chloride were added in the above order. Heating and stirring were continued for an add itional hour and then the beaker was placed in an ice bath to be codied while excess^potassium permanganate was destroyed by adding acidified sodium sulfite solution. Concentrated sulfuric acid was added dropwise in excess to make the reaction mixture strongly acidic. The precipitated manganese dioxide was dissolved by adding additional solid sodium sulfite. Approximately 90 g of sodium sulfite was used before the mixture turned clear, After standing over night the precipitated acid was extracted into three portions of ether. The combined extract was washed once with water and then three times with 100 ml saturated sodium bicarbonate solution. The combined aqueous layers were then acidified with concentrated sulfuric acid, caus ing the ketopinic acid to precipitate. The yield after filtering and drying jln vacuo was 20-25 g (22-2?$ based on ■the amount of 1O-camphorsulfonic acid used), mp 212-2l8°C, lit.^2 233-23^°C. This crude white ketopinic acid was used directly in the synthesis of l-bromo-2-oxoapocamphane. ,The ether extract from above was dried over anhydrous •magnesium sulfate, and the solvent was then stripped off 31 under reduced pressure to give approximately 3 g of 10-chlorocamphor, mp 130-133°C» lit.'*0 133°G; ir (CCl^) 5.75 (C=0), 7.05, 7.19 and 7.29^1 nmr (CCl^) 60.99 (singlet, 3, CH^), 1.15 (singlet, 3, CH^), 3.7 (quartet, 2, J=12.5 Hz, C—10 CHg), 1,80 (multiplet, 6H), and 2.29 (broad, 1, C—2 + —■ h ) ppm._ i +8 1O-Chlorosulfoxide Camphor. In a 100 ml round-bottomed flask provided with a reflux condenser with calcium chloride tube, p-toluenesulfonyl chloride, 7.6 g (0.04 mole), was mixed with 7.0 g (0.09 mole) of dry pyridine and the mixture heated on a steam bath. To this mixture was added in small portions over one hour 9*5 g (0.038 mole) 10-camphorsulfonyl chloride. The reaction mixture turned dark brown and was heated for an additional hour and 45 minutes. When it cooled to room temperature a viscous paste?-like material was obtained which was diluted with 'water and extracted with ether. The ether layer was washed , ! with dilute hydrochloric acid and then with saturated I ■ ^ sodium chloride solution. The ether layer was dried over ; 1 |anhydrous magnesium sulfate, treated with charcoal, and concentrated at reduced pressure to give 4,8 g (55% yield) j 32 of reddish^crystalline 1O-chlorosulfoxide camphor, mp 83-85°C, lit.^8 84.5-85.5°C; ir (CCl^) 1758(b), 1150(b), 1136(s), 1050(m), and 2960 cm"1(s)• Oxidation of 1O-Chlorosulfoxide Camphor in Sulfplane. A mixture of 4,8 g (0,021 mole) of 1O-chlorosulfoxide camphor, 3.7 g (0,047 mole) of dry pyridine, and 50 ml of sulfolane was placed into a 200 ml three-necked flask fitted with,a reflux condenser, magnetic stirring bar, calcium chloride tube, thermometer, and a 125 ml dropping funnel. Over a period df one and one-half hours a solution of 10 g (0,063 mole) of potassium permanganate in 60 ml of sulfolane was added dropwise to the stirred mixture in the reaction flask at a rate such that the reaction temperature was kept below 80°C, The mixture was stirred for another half hourj then an acidified solution of sodium sulfite was added to it to get rid of any unreacted potassium permanganate. The 'mixture was made strongly acidic by adding an excess of I I 'concentrated sulfuric acid. An additional amount of j ( i : crystalline sodium sulfite was added as necessary to dis- j I solve the resulting manganese dioxide. After the solution | i turned clear, it was extracted with ether in a continuous 33 extracter overnight. The ether solution was washed with water to remove the sulfolane, dried over anhydrous magnesium sulfate, and evaporated to dryness to yield 2«56 g (68% yield) of ketopinic acid. eg A-] l-Bromo-2-oxoapocamphane. * Ketopinic acid, 20 g (0.11 mole), was dissolved in 35 ml of methylene chloride in a 300 rol three-necked round-bottomed flask equipped with a stirrer, condenser and pressure equalizing addition .funnel. Red mercuric oxide, 23 g, and anhydrous magnesium sulfate, 10 g, were added to the flask. An additional 160 ml of methylene chloride was poured into the flask, and the mixture was stirred and heated up to reflux. Bromine, 18.7 g (0.12 mole), was placed in the addition funnel and was added to the reaction flask dropwise. The addition was maintained at such a rate that the evolution of carbon dioxide could be controlled. After the addition was i :completed, the mixture was heated under reflux for two more j : I jhours. Care was taken to shield the apparatus from uv j • i ' flight during the course of the reaction; The reaction 1 | :mixture was cooled to room temperature and was washed with • j jtwo 500 ml portions of 1$% aqueous potassium iodide ___j 3^ solution. During this washing the mixture turned red, then yellow, and finally clear. The organic layer was then washed twice with 1 aqueous sodium thiosulfate solution to get rid of any free iodine. Any unreacted ketopinic acid was removed from the organic layer by two extractions with saturated sodium bicarbonate solution. Then the methylene chloride layer was washed once with saturated sodium chloride solution, dried over anhydrous magnesium sulfate, and decolorized with charcoal. After distilling off the solvent under reduced pressure, 20 g (8k% yield) of crude l-bromo-2-oxoapocamphane was left behind as a residue. The ketone was recrystallized from pentane to give a material mp 182-185°Cj ir (CHCl^) 5«7 (G=0), 7.05 (methylene band Ot to carbonyl), ?,2, 7,3/i (gem-dimethyl groups). After further purification by sublimation, the :l-bromo-2-oxoapocamphane had a mp 192-193°G, lit.-^ 193- I195°G. I l-Bromo-2-oxoapocamphane in Methanolic Potassium Hydroxide at Room Temperature. In a 200 ml round-bottomed flask were placed 2.013 g (0.009 mole) of l-bromo-2-oxoapocamphane and 50 ml of 2N methanolic potassium hydroxide. The mixture 35 was stirred continuously at room temperature for twelve hours, during which time aliquots of the reaction mixture were pipetted out at regular intervals for bromide ion determination by the Volhard procedureAt no time during this period could bromide ion be detected by this ti- trimetric method. l-Bromo-2-oxoaoocami>hane in Refluxing Methanolic Potassium Hydroxide. l-Bromo-2-oxoapocamphane, k,k2 g (0,02 mole), and 100 ml of 5»6n methanolic potassium hydroxide were stirred and heated under reflux for ^5 hours in a 300 ml round-bottomed flask equipped with condenser and drying tube. The reaction mixture was then cooled to room temper ature and acidified with dilute hydrochloric acid before extraction with ether. The ether layer was further extract ed with 5% sodium bicarbonate solution and then washed with saturated sodium chloride solution. After drying over anhydrous magnesium sulfate, the solvent was distilled j t off under reduced pressure to give 2.58 g of neutral j i ;residue, consisting of eight to nine compounds with shorter glpc retention times than the starting material.^ThM'O bicarbonate layer was acidified with dilute hydrochloric acid and extracted with ether, and the ether extract was dried and concentrated to yield 1,32 g of acidic materials, Diazomethane was added to convert any acids to methyl esters. Gas-liquid chromatography showed twenty-seven products, among which 12$ (relative to the others) was the Favorskii rearrangement product, 5*S-dimethylbicyclo[2.1,li hexane-1-carboxylic acid, which,^as the methyl ester, had a retention time of 5*5 minutes; All except one compound had longer retention times than the Favorskii rearrangement product. Only 2$ of the materials recorded on the chromato gram had a retention time of 5 minutes. Other major components were detected at 6,5 minutes and 7*2 minutes, both in 5$ quantity, and 8$ each of two others at 9*8 minutes and 11;5 minutes. The 22 and 23 minute peaks represented 25$ and 30$ of the mixture, respectively. No attempts were made to identify these compounds, i Bomb Reaction of l-Bromo-2-oxoa-pocanrphane in 2N Aqueous : Fotassium Hydroxide Solution. In a ^00 ml metal bomb was I iplaced 260 ml 2N aqueous potassium hydroxide solution, I Nitrogen was allowed to bubble through the solution for 10-15 minutes before the addition of 500 mg (0;0023 mole) 37 of l-bromo-2-oxoapocamphane and the sealing of the bomh, The bomb with its contents was rocked back and forth contin uously and heated at I55f+ 10°C for 18 hours. When cooled to room temperature the reaction mixture was acidified with dilute hydrochloric acid and extracted with ether, which was further extracted with 5$ sodium bicarbonate solution. The organic layer was dried and concentrated, and kkfo of the starting material was recovered; The bicarbonate wash was acidified with dilute hydrochloric acid and extracted with ether, which in turn was dried and removed under reduced pressure to leave an acidic residue, 176 mg. Gas- liquid chromatography of an esterified sample showed 89$ of acidic residue to be 5»5-dimethylbicyclo[2.1»l) hexane- 1-carboxylic acid; The ir, nmr, and GC retention time of bothfethe acid and the methyl ester all agreed with authentic material^; ir (CCl^) 5»9 (C=0), 7i2, 7,3 (gem-dimethyl < * r groups), Jity* (OH); nmr (CCl^) 60.91 (singlet, 3*, tt-5 ~CH^), l;l^ (doublet, 1, C-6 —endo H), 1.28 (singlet, 3» C-5 “CH^),1 t 1.80 (multiplet, C-2 —Hg and C-3iJ_H2)» 2;02 (multiplet, -1, C-6 -exo H), 2,29 (broad, 1H), and 3:63 (singlet, 3, ' l : C-1^ —COOCH^)• When the same reaction was carried out at j 38 250 + 10°C, many other compounds resulted, although 5,5“dimethylbicyclo(2.1•l}hexane-1-carboxylic acid was still the major component. Bomb Reaction of l-Bromo-2-oxoa~pocanrphane in 2N Aqueous Barium Hydroxide Solution. l-Bromo-2-oxoapocamphane, 500 mg (0.0023 mole), was heated in 260 ml 2N aqueous barium hydroxide solution in the presence of nitrogen in a 400 ml metal bomb at 150 + 10°C for 18 hours. The mixture was then acidified and extracted with ether• The ether layer, after extraction with sodium bicarbonate solution, was dried and concentrated to recover 9 of the starting material. The bicarbonate wash, after acidification with dilute hydrochloric acid, was further extracted with ether to yield 65 mg of acidic materials, of which was 5,5-dimethylbicyclo[2il,l] hexane-1-carboxylic acid. i CHAPTER IV DISCUSSION When a bicyclo(2,2«l) heptyl system rearranges to a compound with one less carbon atom in the ring, a great amount of strain is introduced. On the other hand, the fact that Favorskii rearrangements introducing an even greater strain-energy increase may proceed more readily under milder reaction conditions than those required in the present study, suggests that there may be factor(s) other than ring strain involved in the process; For exam ple, 1 dichlorobicyclo(2.2,l) heptan-7-one was readily converted by sodium hydroxide powder in tetrahydrofuran at 0-5°C to ^-chlorobicyclo(2.2;o] hexane-1-carboxylate,^ .'Presumably, the amount of energy gained from the formation i ,and solvation of the chloride ion and the carboxylate anion 1 'of 4-chlorobicyclo(2;2;o)hexane far exceeds the amount of 'energy introduced by ring strain in the product; 40 HO CO O' CL H.- C. Brown, in an effort to explore the effect of structure in bicyclic systems on chemical reactivity found that 7-norbornanone is exceedingly more reactive than 2-nor- bornanone^ toward addition of hydride (BH^~) to the carbonyl centers'. o reactivity! » If l-bromo-2-oxoapocamphane is to undergo Favorskii re arrangement by the semi-benzilic mechanism in the presence of a base to yield 5»5~dimethylbicyclo[2.1*l] hexane- 1-carboxylic acid, one might suspect that the activation ienergy of the reaction would be higher than for the same j . j * t reaction in a ?-oxo analog. In this present study, it was j i • observed that at room temperature the reaction of 1-bromo- i 1 ,2-oxoapocamphane in methanolic potassium hydroxide did not ■ proceed to any significant extent. Thereforei the reaction conditions were made more vigorous "by raising the reaction temperature. Sublimation is a convenient method of purifying l-bromo-2-oxoapocamphane, which readily sublimes at 110°C. In order to avoid the problem of sublimation of a reactant when high temperature is essential to a reaction, it became necessary to perform the reaction in a sealed tube or bomb; A sealed reaction vessel would not only solve the problem of sublimation when its contents are shaken well during the course of the reaction; it also would make it possible for a low boiling liquid, such as water, to boil at high temperature, thus providing a high temperature reaction medium. The reaction of l-bromo-2-oxoapocamphane in methanolic potassium hydroxide solution in the presence of oxygen ^yielded many acidic products; about twenty-seven in all. ■These compounds may be oxidation products, or some of them ;may result from condensation reactions or by Favorskii ^rearrangement of compounds derived from condensation iproducts. Br Br OH • r 2 o OH :oo' Br However, when the reaction proceeded in an aqueous medium at 150°C under nitrogen, the expected Favorskii rearrange ment product, 5,5-dimethylhicyclo[2,'i,l] hexane**!-car boxylic acid, became the major product. The solvolysis of l-bromo- 2-oxoapocamphane in aqueous bases may lead to the formation of a dianionj which can be expected to be more reactive than the single anion species formed from the attack of a methoxide ion at the carbonyl center of the bromoketone. 43 The difference in reactivity between the two anion species may possibly be the cause of the difference in product yields in the two different reaction medium. When the reaction was carried out at 250 + 10°C in the presence of nitrogen, again, many products were observed. This may be due to fragmentation or ring opening of the bicyclo[2.1,l] hexane ring. COOH ■cooH In a study of the thermal decomposition of methyl cyclo- butanecarboxylate, it was suggested that if a biradical is involved in the 'ring cleavage process, the biradical formed from cyclobutane carbonyl derivatives would be expected to possess more resonance energy than a biradical formed from an alkylcyclobutane^ t and that an increased resonance energy for the biradical might result in a lower energy for the activated complex through which the biradical was derived. This is to say that there is a decrease in act- ; t ivation energy for carbonyl derivatives in the process, i Although the activation energy for the thermal decomposition @ 6 of cyclobutane is about 62 kcal , the approximate energy of activation for the thermal decomposition of 5»5-dimethyl- bicyclo(2.1,l] hexane-l-carboxylate is ^7 kcal. One may also speculate that polymerization of the fragmented species may also take place, since it was noted that some of the products have much longer retention times than 5»5-dimethyl- bicyclof2,1,ljhexane-l-carboxylic acid. Moreover, the pro duct mixture reacted with bromine in carbon tetrachloride, indicating the presence of unsaturation. It is not clear whether the Favorskii rearrangement of l-bromo-2-oxoapocamphane proceeds by way of a cyclo- propanone intermediate or by the "semi-benzilic rearrange*^’ ment" mechanism. However, a yield as high as 99f° of 5,5“dimethylbicyclo[2.1,l) hexane-l-carboxylic acid based on the amount of reacted l-bromo-2-oxoapocamphane has been obtained. Also, no 5»5“dimethylbicyclo(2,1,l) hexane-6- ;carboxylic acid has been detected in the reaction. The 1 I I characteristic bridgehead protons at 2.70 tau for ,5'i5“diniethylbicyclo(2.1 .l] hexane-6-carboxylic acid were i .absent from the nmr spectrum of the reaction mixture. Only the rearrangement product with the carboxylate group at the_j bridgehead can he derived from the "semi-benzilic" mechan istic pathway. If the reaction proceeded by the cyclo- propanone intermediate, the rearrangement product might include the two isomers of 5»5“dimethylbicyclo[2,l .l") hexane- 6-carboxylic acid. Nevertheless, if this compound should be present at all, one might not expect to find it in a significant amount. This is due to the fact that for an unsymmetrical fll-bromo ketone, the)cyclopropane ring usually cleaves to form the more stable of the two transient car- banions, and a tertiary carbanion at the bridgehead is presumably less stable than a secondary carbanion at the C—6 position. BIBLIOGRAPHY J. Meinwald and Y. C, Meinwald, ''Advances in Alicyclic chemistry^!) Vol. I, pp, 1, Academic Press, New York, 1968. R, Srinivasan and-F, I, Sonntag, J, Am. Chem. Soc,. J3£, 407 (1967). K. B, Wibergi B, Ri Lowry, and T. H. Colby, ibid.. 83, v > aW 3998 (1961). L. Horner and E, Spietschka, Chem. Beri. 88, 93^ (1955). J» Meinwald, A. Lewis and P, G. Gassman, J. Am.tiGhem, Soc., 82, 2649 (I960). 1 1 ' ■ - w w J, Meinwald, A, Lewis and Pi G, Gassman, ibid,, 84, 977 (1962). 1 J, Meinwald, Pi Gi Gassman, ibid., 82, 2857 (I960), * — mrnmmmmmmm j I J, L, Charlton, P, de Mayo, and L. Skatteb^l, Tetra- 1 hedron Lett.. 4679 (1965). P. T, Bond, H, L, Jones and L, Scerbo, ibid., 4685 ! t (1965); ! 47 10. R» S. H. Liu and G. S. Hammond, J. Am. Chem. Soc.. 89, 4936 (1967). 11. R. Srinivasan and K. H. Carbugh, ibid., 89, 4932 (1967). 12. Ji D. White and D, Ni Gupta, Tetrahedron. 25, 3331’ vw v (1969). 13. K. Ebisu, Li B. Batty, J. M, Higaki and Hi 0. Larson, J. Ami Chem. Soc.. 88, 1995 (1966), 1 ■ .1 r . j..i — 1 r r "■ ■ mu - r - r - ■ r *ir - W * / 14. A. Ei Pavorskii, Chem. Abstri, 7j 984. 15* A. E. Favorskii and V, N, Bozhovskii, ibid., 9» 1900. 1 ~ " WVW* l6i A. E. Favorskii and V. N. Bozhovskii, ibidi, 18, 1476. 17* J. S. Hine, "Physical Organic Chemistry," pp. 131-133» 188, Mcigraw-Hill, New York, 1956. l8i G. Richard. Comot. Rend., 197. 1432 (1933). ' 11 ' 11 <MAAAVl/ 19« F. G. Bordwell, R. R. Frame, R. G. Scamehorn, J. G. Strong, and S. Meyerson, Ji Ami Chem. Soci, 6704 (1967)i 20. Ji M. Cornia and J. Salauni Bull. Soc. Chim. France, 1957 (1964). 21i Ai C. Cope and E. S. Graham, J. Am. Chem. Soc.. 73. 1 " ' ' ......VSAAA 4702 (1951). 48 22. P. E. Eaton and T. W. Cole, Jr., ibid.. j36, 962 (1964); 23; P. E; Eaton and t ; W. Cole, Jr., ibid;-; 86; 3157 r ' ■ - r" " * ,l_ VVVW (1964); 24. j; Bredt, Ann.. 437, 1 (1924). 25. A; Si Kende. Ore. Reaction. 11. 26l (i960); 26. R. b ; Loftfield, j; Am. Chem. Soc;. 73, **707 (1951 )i 11 r ^ ’ .. * L MaV 27. R. B. Loftfield, ibid., 72, 632 (1950). 1 ■ 11 ■ vvv\V 28. w; D. McPhee and E; Klingsberg, ibid.. 66, 1132 (19&4). 29; H. 0. House and F, A. Richey, J. Ore. Chem., 32, 2151 (I967)i 30. A. Nickson and N; H. Werstiuk, J. Am. Chem; Soc;. 8jg, 39i4; 3915 (1967); 31; J. G; Burr and M, j; S, Dewar; j; Chem; Soc;, 1201 (195*0'; 32; j; G; Aston and J; D. Newkirk, J. Am. Chem. Soc;. 73, i r< j i ' > 1 - . 1 ‘ 1 — t -t y.ArfVN/ 2900 (1951). •33. A, A, Sacks and J. G. Aston, ibid.. 7^, 3902 (1951)• 1 34; G; S. Hammond, in "Steric Effects of Organic Chem^^gr , istryv" pp« 439-441, M, S. Newman, edit., John Wiley and Sons, New York, 1956. 49 30 C. Raone. Acta Chem; Scand.. 21, 163 (1967) • ■ > > n - « ■ » ■ r i i . i v w w ^ 36. E. W; Warnhoff, C. M, Wong; and W, T; Tai, J. Org. Chem.; 32, 2664 (1967). 1 vt/W 37» E, Wi Warnhoff, C; M, Wong, and Wi T, Tai, Ji Am; Chem. Soc.. 90, 514 (1968). ' WW 38. J; A; Berson, "Molecular Rearrangements?" Part I, P; de Mayo, Ed., John Wiley and Sons, New York, 1963# 39* J; W. Huffman and J. E, Engle, j; Org; Chem.. 24, 1844 I ***/ (1959)i 40, K; Ehisu, L, Bi Batty, J. M-; Higakij and Hi 0. Larson, J; Am. Chem. Soci. 87. 1399 (1960. "-■■■j r r — - ■ in m u . i i i j v V k A / 41, H, 0; Larson*, T. C. Ooi? W. K, H; Luke1 , and K; Ebisu, j; Org. Chem.. 34, 525 (1969). 42; P. Di Bartlett and L. H. Knox, J; Am. Chem. Soc.. 6l, v V W 3184 (1939). .43i P. D; Bartlett and L; H; Knox, Org. Syn.. 45, 14 iliO (1965); 1 44; G, Opitz and H; Adolph, Angew Chem.. 74, 77 (1962)1 T. J. Wallace, Quarterly Review. 20, 67 (1966), 45i G, Stork and Ii J; Borowitzi Ji Am; Chem, Soc.. 84. " " 1 1 1 1 1 1 " J l ’ ■ " ... " ■ " ‘ “■ * wvW 9 313 (1962). 3 ; V - 50 k6, W. E, Truce, J, J. Breiter, D, J. Abraham, and J* R. Norell, ibid., 84, 3030 (1962). n ■ ,.■ i_ ' \AAA/ 4-7• Ei Wedekind, Di Schenk and Ri Stusser, Chem. Ber.. 56, vw 633 (I923)i lJ-8. J. Stratine. Rec. Traveaux Chimi P-BL . 83. 9^ (1964). r " 1 r 1 - 11 T 1 r ' “ ' 1 1 1 J vxa7 ^9. Ji F. King and T. Durst, Tetrahedron Letti. 1963» 585* 50. G. Gi Henderson and J. A. Mair, J. Chem'i Socii 1155 (1923). 51. Fi A singer’ , Beni., 7£B, 191 (19^4)i 52i H. F. Herbrandson, W. S. Kelly and J. Versnel, J. Ami Chem. Soc.. 8$, 3301 (1958). 53® E. M. Kosower, "Physical Organic Chemistry*" John Wiley and Sons, Inci, New York, 1968, 54, Ji E, Nordlanderi S; P. JindaT, Pi v. R. Schleyer, Ri C. Fort, Jr., Ji J. Harper, and Ri Di Nicholas^ Ji Am. Chem. Soc.. 88. 1(475 (1966). r ' - ' - * ~ ~ ' A 1 ~ 1 r i ‘ ' L- J ■ ■ Vw^ I 55* Si Winstein, Bi ,Ki Morse, E, Grunwald, Ki C. Schreiber, and Ji Corse, ibidi. 74, 1113 (1952). 1 1 W w 56. W. G. Dauben, J. Li Chitwood, and K, V. Scherer, Jri, ibid., 90, 'II01 IK 11968*). 1 V s W 51 57* F, W, Baker, H, Di Holtz and L, M. Stock, J. Org. Chem.. 28, 314 (1963). r-r r ~ VW 58i P. W; Jennings and Ti Di Ziebarth, ibid.; , 3216 (1969). 59i V; Spazianoi Ph. D« thesis! Villanova University, Pennsylvania, 1969i 60, W. A; Waters, "Vistas In Free Radical Chemistry!" pp'. 229~232, Pergamon Pressi Ltdi’ , London, 1959. 61. K. V. Scherer, Jr.vand R. Thomas, unpublished results. 62i J'. Fritz and G. Schenk, Jri, "Quantitative Analytical Chemistry!" ppi 154-158, Allyn and Bacon, Inc., Boston, 1966. 63• We are indebted to H, 0. Larson for the gift of the authentic sample, 5» 5-diroethylbicyclo[2 il»l] hexane- l-carboxylic acid. 64-. Ki V‘ ; Scherer, Jr.! Tetrahedron Lett.; b6, 5685 (1966), 65. H, C. Brown and Ji Muzzio'i J. Am. Chem. Soc.i 88, 2811 v v w 66i Mi Zupan and W, Di : Walters-, Ji Am. Chem. Soc.. £6, 173 (1964). '67. F, 0. Rice and K, K. Rice, "The Aliphatic Free Radi^?,l cal!3! p. 113, Johns Hopkins Press, Baltimore, 1935* j APPENDIX 52 9.0 ■ > —i — 8.0 7.0 6.0 100 200 ;s r Figure i .— 1H ranr spectrum of l-bromo-2-oxoapocamphane? « 4.0 3.0 2.0 1 . . . Figure 2,— H nmr spectrum of methyl 5,5-di- 1. 0 o methylbicyclo[2.1.l]hexane-l-carboxylate. MICRONS 4.0 5.0 6.0 7.0 8.0 9.0 ■ 0 - 0 , 00- - 0 - 0 - Xu; ■0-1: "O '2; r0'*3- '0-3 40-4: ■Br -O-if -0-4: -0-5- 0-5 l t j + ’ - i t f i - o j ■10: - 1 - 0 : r e d : 3000 /AVENUMBER (CM-) 2500 2000 1800 1600 1400 1200 WAVENUM3ER (CM 1000 800 600 Figure 3»““ ir spectrum of l-bromo-2-oxoapocamphane. 0\ MICRONS 5.0 3.0 4.0 8.0 9.0 6.0 7.0 ■ o - o H - ■00 0 - 0 - - 0 - 0 - 0 - 2 i 0-2- : o - 2i 0'4r 0;4- , ).4. 04H • C O O H o - a - A5r Jill TT1T • 1 - 0 -1-0 - -.10 h e 3500 3000 WAVENUMBER {CM-1 ) 2500 2000 1800 1600 1400 1200 1000 WAVENUMBER (CM") 800 Figure 4,~ ir spectrum of 5,5,-dimethylbicyclo(2,1.l] hexane-l-carboxylic acid. MICRONS 3.0 4.0 5.0 6.0 7.0 8.0 9.0 i b - o - 00 •02 -0-2 0-2 i i x r •0-4 -0-5 -0-5- j j ± #5 •10- - 1 - 0 .X i; ml titf JILL 3000 2500 1000 2000 1300 1600 1400 1200 300 WAVENUMBER (C M 1) WAVENUMBER (C M '1 ) Figure 5.— ir spectrum of methyl 5,5-dimethylbicyclo(2,1,l)hexane-1-carboxylate. I h i i i — j U iXJu . 1 . . : . X - i A. l u I L 6.0 . [ 1 -0 1 6 0 Figure 6.— mass spectrum of methyl 5i5“dimethylbicyclo[2.19l1 hexane-1' carboxylate.

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Creator Fong, Wendy Wan-Tek (author)

Core Title A study of the reaction of 1-bromo-2-oxoapocamphane in base

Degree Master of Science

Degree Program Chemistry

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Advisor Scherer, Kirby V. (committee chair), Brown, Ronald J. (committee member), Burg, Anton B. (committee member)

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