75-3012 BIRNBERG, Gary Harold, 1948- I SYNTHESIS AND REACTIONS OF SELECTED MONOSUBSTITUTED DIBENZOSEMIBULLVALENES, SEMIBULLVALENES, AND BULLVALENES. j The Ohio State University, Ph.D., 1974 | Chemistry, organic ( ! | 1 Xerox University Microfilms , Ann Arbor, Michigan 48106 THIS DISSERTATION HAS BEEN MICROFILMED EXACTLY AS RECEIVED. SYNTHESIS AND REACTIONS OF SELECTED MONOSUBSTITUTED DIBENZOSEMIBULLVALENES, SEMIBULLVALENES, AND BULLVALENES DISSERTATION Presented in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy in the Graduate School of The Ohio State University By Gary Harold Bimberg, B. Sc. ***** The Ohio State University 197^ Reading Committee: Approved By Dr. Leo A. Paquette Dr. Robert J. Ouellette Dr. John A. Secrist, III Department of Chemistry DEDICATION To my parents and siblings ii 1 'Would you tell me, please, which way I ought to go from here?1' ''That depends a good deal on where you want to get to,'' said the Cat. ''I don't much care where said Alice. ''Then it doesn't matter which way you go,'' said the Cat. ''... so long as I get somewhere,1' Alice added as an explanation. ''Oh, you're sure to do that,’1 said the Cat, ''if you only walk long enough. '' Lewis Carroll iii ACKNOWLEDGMENTS The author wishes to express a profound indebtedness to Professor Leo A. Paquette for the opportunity to work both with and for him and to the personnel of Armand’s Army ttho made my stay in Cowtown enjoyable. Special thanks to Mr. J. M. Geckle without whose dedication to someone else's research this thesis would not have been possible at this time. iv VITA March 6, 19bQ ............. Born - Brooklyn, New York 1967........................... A. A., Ml ami-Dade Jr. College, Miami, Florida 1969........................... B. Sc. , with honors, University of Florida, Gainesville, Florida 1969-1972 ...................... Teaching Assistant, The Ohio State University, Columbus, Ohio 1972-1973 ...................... Goodyear Tire and Rubber Fellow, The Ohio State University, Columbus, Ohio 1973-197^ ................ Research Assistant, The Ohio State University, Columbus, hio 197^........................... Hi. , The Ohio State University, Columbus, Ohio PUBLICATIONS Leo A. Paquette and Gary H. Bimberg, ' '5-Dibenzosemibullvalenylcar- binyl Carbene and Carbonium Ion. Some Observations on the Fate of Reactive Groups Attached to the Bridgehead Carbon of a Non- fluxtional Semibullvalene,' 1 J. Amer. Chem. Soc., 9j+, 16k (1972). Leo A. Paquette, Gary H. Birnberg, Jon Clardy, and Bruce Parkinson, ''Stereoselective 1,4-Bromination of Semibullvalene and Tri-n- butyltin Hydride Reduction of the Dibromide,'' JCS Chem. Commun., 129 (1973)- FIELDS OF STUDY Major Field: Organic Chemistry v TABLE OF CONTENTS Page DEDICATION.................................................. ii ACKNOWLEDGMENTS.............................................. iv VITA........................................................ v LIST OF TABLES............................................... vii LIST OF FIGURES............................................. viii - INTRODUCTION................................................ 1 RESULTS AND DISCUSSION Part I. 5-Dibenzosemibullvalenylcarbinyl Carbene and Carbonium I o n ................................... l4 Part Ila. Bromination of Semibullvalene.................. 28 Part lib. Synthesis of Selected Monosubstituted Semibullvalene s 3 2 Part lie. Reactions and Properties of Selected Mono­ substituted Semibullvalenes..... *........ 4l Part III. Synthesis and Reactions of Selected Mono­ substituted Bullvalenes ......... 55 EXPERIMENTAL................................................. 66 REFERENCES............................................. 123 vi LIST OF TABLES Table Page I Decomposition of Dibenzosemibullvalene-5-Carboxaldehyde Tosylhydrazone (51) ....................... 15 II Results of Direct and Indirect Addition of PTAD to Various Monosubstituted Cyclooctatetraenes ........... 55 III Summary of Conditions for Conversion of Tetracyclic Dienes to 9jlO-Diazabasketanes ...................... 57 IV Summary of Conditions for Transformation of 9 >10- Diazabasketanes to 9>10-Di&z&snautanes ........... 38 V Variable Temperature Rnr Shift Data for 106d 5=^ 106'd. (6, 60 MHz, TMS) .................................... 42 VI Variable Temperature Rnr Shift Data for 107d ^ 107.' d (6, 60 MHz, TMS) .................................... 44 VII LIS Rnr Data for 11£ (fi, 60 MHz, TMS) .................. 49 VIII LIS Rnr Data for 114 (6, 60 MHz, TMS).................. 51 IX LIS Rnr Data for 14^ (6, 60 MHz, TMS) .......... 62 X Decomposition of Bullvalenylcarboxaldehyde Tosyl­ hydrazone 115 vii LIST OF FIGURES Figure Page I Newman projection along the 6-7 bond of 6 ^ .............. 25 II Newman projection along the 5-6 bond of 7 1 ..... 25 III Plot of chemical shift vs mole $ of Eu(fod)3 for 11 ^ .... 50 IV Plot of chemical shift vs mole $ of Eu(fod)3 for lift- 52 V Plot of chemical shift vs mole $ of Eu(fod)3 for 1^ 5 .... 65 viii INTRODUCTION 1 Subsequent to the prediction by Doering that bullvalene (l) should be a molecule capable of degenerate Cope rearrangement to the extent that it would be totally fluxional (1,209,600 possible valence isomers), a great deal of attention has been given to molecules that are 2 inherently capable of comparable valence isomerization. For example, etc. semibullvalene (2), a close structural relative of 1, has attracted much 3a interest since first synthesized and initially reported to have a pmr ' 1 spectrum which is temperature independent from -110° to +117°. Re- 4 cently, Anet reported the temperature dependent prar spectra (-110° -♦ -165°) for 2, observed coalescence at -143°, and calculated the energy of activation for the degenerate Cope rearrangement of 2 to be 5*1 kcal/mole, the lowest yet found. This is slightly higher than the 2.3- 5 3*3 kcal/mole value MIHDO/2 calculations had predicted. The synthesis of bullvalene was first accomplished in 80$ yield by the irradiation of that cyclooctatetraene dimer which melts at 76° 6,7 (j5). Later a ' 'rational'' synthesis of 1 appeared based upon the 1 preparation of barbaralone (4) from benzene in five steps, and ring expansion of this ketone with diazomethane to give bullvalone (5) 8 together with.epoxide 6, Subsequent borohydride reduction of 5_, acetyl- ation of the alcohol, and pyrolysis of the acetate at 345° gave .1 admixed with cis-9,10-dihydronaphthalene (j). This particular route suffers from a large number of steps and the several tedious separations involved. I c h 2n 2 1) NaBH4 2) Ac20 3) 3^5° A rather novel pathway to 1^ in three steps from methane(tri-a- 9 diazoacetone) (8) has appeared recently. The treatment of 13 in reflux- ing xylene with anhydrous copper sulfate in thioanisole under high dilution conditions afforded in 2$ yield the '’bullvalenetrione’' 9. Subsequent reaction of the tris-tosylhydrazone of 9_with excess methyl- lithiura gave 1 in approximately 20$ yield. 0SMe 1) TsNHNH2 HC(CH2C0CHN2)3 CuS04 2) MeLi 8 9 1 0 The interconversions of various (c h )io hydrocarbons also provide pathways for the synthesis of 1. For example, irradiation of bicyclo­ ll, 12 [4.2. 2]deca-2,4,7,9-tetraene (10) affords 1 in 64$ yield, while the photoisomerization of cis-9,10-dihydronaphthalene (T) gives 1 in 13,14,15 addition to 10, iumibullvalene (11), and naphthalene (12). The formation of 1 from 7 has been suggested to arise from the conversion 10 hv 1 + 10 11 12 of 7 to 10 in the primary photoprocess, followed by further excited 14 e, state reaction of 10 to form L, Of the above routes to 1, Schroder’s is at present the most convenient. Access to substituted bullvalenes has evolved principally from 2a the chemistry of 1 and Methylbullvalene (lj?) and phenylbullvalene (lA), for example, have been prepared by the action of methyllithium and phenylmagnesium bromide, respectively, on 5_ followed by dehydra- 8 tion. Bromobullvalene (15), available from the bromination-dehydro- 1) MeLi l) 0MgBr A lA 16, 17 halogenation of JL, has been a key compound in providing convenient 16-20 routes to a number of other substituted bullvalenes. Chlorobull- 18 valene (l6) has been obtained in a similar manner, while the remaining halobullvalenes have been derived from 1£_. Thus, when bullvalenyl- magnesium bromide (IT) was allowed to react with iodine, iodobullvalene (18) resulted, while the action of silver fluoride on 15, or 18 furnished 18 fluorobullvalene (19) • Conversion of 15 to the various alkyl ethers l) Br2 1) S0C12 •Br 2) KOtBu 2) KOtBu 15 16 20 takes place upon treatment of 15 with the corresponding potassium Mg 15 MgBr 17 AgF AgF 18 2SL 16, IT alkoxide in dimethylsulfoxide. Carbonylation of Grignard reagent MeMgBr 15 15 >. — DM30 OR 20 CuSR 17 in the usual manner gives the carboxylic acid -21, esterification of which with diazomethane leads to carbomethoxybullvalene (22). Reaction of 15^and 17 in the presence of cobalt(ll) chloride gave bibullvalene (2p). Similarly, methylmagnesium bromide was coupled to 15_ to give Ip. The thioethers 24 were prepared by .the action of copper(i) alkylsul- 20 fides on 15. CH2N2 CO2CH3 17 23 Syntheses of substituted bullvalenes based on the interconversion of (CH) 10 hydrocarbons are limited due to the relative inaccessibility of the necessary functionalized (CH)^ precursors. Three known examples of this route are the photoisomerizations of 7,8-diphenylbicyclo[4.2. 2]- 21 deca-2,4,7,9-tetraene (25), cis-9,10-dihydro-9,10-dicarbomethoxy- 8 22 naphthalene (26), and isomers of chlorofluorotricyclo[4.2.2]deca-