The scope of the intramolecular diazoalkane-carbonyl reaction, described in earlier papers in this series, has been extended by application to (a) 2-carbethoxycycloalkanones carrying acyclic side chains at the 2 position containing potential diazoalkyl moieties and (b) cycloalkanones carrying cyclic side chains at the 2 position containing potential diazoalkyl moieties. Of the several compounds studied, the three most synthetically useful ones are 2-carbethoxycyclopentanone carrying a three-carbon acyclic side chain (forming the bridged ring ketone 6 as the major product), 2-carbethoxycyclohexanone carrying a three-carbon acyclic side chain (forming the bridged ring ketone 9 as the major product), and cyclohexanone carrying an N-nitrosopyrrolidone-containing side chain (forming the bridged ring ketones 25 and 26 as the major products).Earlier papers in this series have described diazoalkanecarbonyl reactions that are (a) intermolecular and involve cycloalkanones and N-nitrosolactamsl and (b) intramolecular and involve cycloalkanones carrying potential diazoalkyl moieties.2 9 3 The present paper is concerned with both of these aspects of the diazoalkane-carbonyl reaction, extending the scope of its application.Reactions of 2-Carbethoxycycloalkanones Carrying Acyclic Side Chains at the C-2 Position Which Contain Potential Diazoalkyl Moieties (5). Following the general procedures that have been previously described,2 *3 2-carbethoxycyclopentanone (la) and 2-carbethoxycyclohexanone (lb) were converted to N-acetyl-( l'-carbethoxy-2'-ketocycloalky1)alkylamines containing cyclopentanone and cyclohexanone rings carrying two-carbon, three-carbon, and four-carbon side chains (4), .as illustrated in Scheme I. Nitrosation with dinitrogen tetroxide yields the corresponding N-nitroso compounds (5).
Scheme IPreparation of N-Nitroso-N-acetyl-( 1'-carbethoxy-2'-ketocycloalky1)alkylamines ( 5 ) 0 9 no -q: -0 3 CHJ, CO,Et (CH, 1a.m = O R = (CH,),, CN R = (CHJ, CN b , m = l 3a,m = 0;n = 1 b,m = 1;n =1 c, m = O;n = 2 d, m = l;n = 2 K = CH,CH=CHCN Za, m = 0:n = 1 b, rn = 1; n =1 c , m = O ; n = 2 d. m = 1: n = 2 R = CH,CH=CHCN e.m=O e,m=O f , m = l f , m = l sa, m = 0; n = I b, m = 1; n = 1 c: m = 0; n 2 d, m =1; n = 2 e, m = 0; n 3 f, nz = 1; n = 3 4 a , m = O n = 1 b, m = 1; n = 1 c, m = 0; n = 2 d, m =l; n 3 2 e , m = O ; n = 3 f, m = l ; n = 3Base-induced decomposition of the compounds carrying two-carbon side chains (5a and 5b) results in the formation of complex mixtures which were not investigated further, Base-induced decompositions of the compounds carrying three-carbon side chains (5c and 5d), on the other hand, proceed smoothly and yield more' tractable reaction mixtures. Thus, potassium carbonate induced decomposition of 5c at 25" gives a mixture containing l-carbethoxybicyclo[3.2.1]octan-8-one (6) and 1,4-dicarbethoxycycloheptanone (7), the alcoholysis product from 6. The structure of 6 is commensurate with a CllH1603 molecular formula, infrared stretching bands at 1760 and 1730 cm-l for cyclopentanone and ester carbonyl ...
