83320-80-3Relevant academic research and scientific papers
Syntheses and Properties of Dimethyldiphenyltetradehydro-trideca-, -pentadeca-, -heptadeca-, -nonadeca-fulvene, and Benzannelated Pentadecafulvene Derivatives
Kuroda, Shigeyasu,Ojima, Juro,Kitatani, Kazuto,Kirita, Mitsuru,Nakada, Tadayuki
, p. 2987 - 2996 (2007/10/02)
Syntheses of 4,9-dimethyl-13-diphenylmethylene-5,6,7,8-tetradehydrocyclotridecene (7), 4,9-dimethyl-15-diphenylmethylene-5,6,7,8-tetradehydrocyclopentadecene (8), 6,11-dimethyl-17-diphenylmethylene-7,8,9,10-tetradehydrocyclopentadecene (9), and 6,11-dimethyl-19-diphenylmethylene-7,8,9,10-tetradehydrocyclononadecene (10) are described.Although examination of the 1H n.m.r. spectra suggested that all of the fulvenes (7)-(10) are atropic, the benzannelated derivatives of pentadecafulvene (8), i.e. 13-methyl-7-diphenylmethylene-14,15,16,17-tetradehydrobenzocyclopentadecene (25), 13-methyl-9-diphenylmethylene-14,15,16,17-tetradehydrobenzocyclopentadecene (26) and 7-diphenylmethylene-16,17,18,19-tetradehydrodibenzocyclopentadecene (27) were prepared in order to examine the tropicity of (8) more closely.Comparison of the 1H n.m.r. spectra of these benzannelated fulvenes (25)-(27) with that of 88) reveals that the nonbenzannelated fulvene 88) is atropic.The influence of benzannelation upon the structure of the molecular skeleton of the tetradehydropentadecafulvene system is also discussed.
