Stereoselective thermal rearrangement of syn-7-(1,2-butadienyl)-1-methylbicyclo[2.2.1]hept-2-ene [syn-7-(3-methylallenyl)-1-methylnorbornene]
作者:James A. Duncan、Robert T. Hendricks、Katy S. Kwong
DOI:10.1021/ja00179a030
日期:1990.11
The synthesis and separate thermal rearrangements of (±)-(1R*,4S*,7S*)-7-[(R*)-1,2-butadienyl]-1-methyl-bicyclo[2.2.1]hept-2-ene (8a) and (±)-(1R*,4S*,7S*)-7-[(S*)-1,2-butadienyl]-1-methylbicyclo[2.2.1]hept-2-ene (8b) are described. Both 8a and 8b are shown to rearrange to (±)-cis-1-ethylidene-3a,4,5,7a-tetrahydro-6-methylindene (9) and (±)-cis-1-ethylindene-3a,4,5,7a-tetrahydro-3a-methylindene (10)
(±)-(1R*,4S*,7S*)-7-[(R*)-1,2-丁二烯基]-1-甲基-双环[2.2.1]hept-2的合成和分离热重排-烯(8a)和(±)-(1R*,4S*,7S*)-7-[(S*)-1,2-丁二烯基]-1-甲基双环[2.2.1]庚-2-烯( 8b) 进行了描述。8a 和 8b 均显示重排为 (±)-cis-1-ethylidene-3a,4,5,7a-tetrahydro-6-methylindene (9) 和 (±)-cis-1-ethylindene-3a,4, 5,7a-四氢-3a-甲基茚 (10) 立体选择性大于 90%。差向异构体 8a 主要产生 (E)-9 和 (Z)-10,而 8b 主要产生 (Z)-9 和 (E)-10,结果与六电子 [σ2s+π2s+π2s] Cope 或八电子一致-electron [σ2s+π2s+(π2s+π2a)] 增强 Cope 过程。立体化学分配(8a