Suprafacial and Antarafacial Paths for the Thermal Vinylcyclopropane-to-Cyclopentene Rearrangement of 1-Ethenylbicyclo[4.1.0]heptane to Bicyclo[4.3.0]non-1(9)-ene
作者:John E. Baldwin、Richard C. Burrell
DOI:10.1021/jo9824091
日期:1999.5.1
The gas phase thermal rearrangement of 1-ethenylbicyclo[4.1.0]heptane at 338 degrees C gives the expected vinylcyclopropane-to-cyclopentene product, bicyclo[4.3.0]non-1(9)-ene. The analogous rearrangement of 1-(2'-(E)-d-ethenyl)bicyclo[4.1.0]heptane takes place with the allylic moiety being utilized in both suprafacial and antarafacial stereochemical ways, for both endo and exo isomers of 8-d-bicyclo[4
1-乙烯基双环[4.1.0]庚烷在338℃下的气相热重排得到预期的乙烯基环丙烷-环戊烯产物双环[4.3.0] non-1(9)-烯。1-(2'-(E)-d-乙烯基)双环[4.1.0]庚烷的类似重排发生于表位和反面立体化学方式的烯丙基部分,用于8-的内和外异构体形成d-双环[4.3.0] non-1(9)-烯。在Ag(fod)和Yb(fod)(3)变换试剂存在下,通过氘核NMR定义的产物比率对应于(79 +/- 2)%表面活性(sr + si)和(21 +/- 2) )%antarafacial(ar + ai)反应立体化学。