Malonate radical cyclisations of methylenecyclopropane derivatives
摘要:
Cyclisations of various methylenecyclopropyl substituted malonate radicals have been studied. Radicals derived from malonates 4 and 9 underwent exclusive 5-exo cyclisation onto the methylenecyclopropane alkene, followed by opening of the resulting cyclopropylmethyl radical, to give methylenecyclohexane products. Radicals derived from malonates 5 and 10 largely gave bicyclo[1.5.0]octane products, in good yields, as a result of 7-endo cyclisation. Cyclisation of the radical derived from malonate 11 gave a bicyclo[1.5.0]nonane derivative in 31% yield, as a result of an 8-endo cyclisation.
Radical cyclisations of methylenecyclopropane derivatives
作者:Christine Destabel、Jeremy D Kilburn、John Knight
DOI:10.1016/s0040-4039(00)93404-x
日期:1993.5
Radicalcyclisations of various methylenecyclopropane derivatives have been studied and it has been found that methylenecyclopropyl propyl radicals undergo exclusive 5-exo cyclisation while methylenecyclopropyl butyl radicals give a mixture of products resulting from 6-exo and 7-endo cyclisation. Attempted cyclisations of methylenecyclopropyl pentyl radicals leads to reduced products only.