Cascade radical cyclisations leading to steroid ring constructions. Regio- and stereo-chemical studies using ester- and fluoro-alkene substituted polyene acyl radical intermediates
作者:Haydn M. Boehm、Sandeep Handa、Gerald Pattenden、Lee Roberts、Alexander J. Blake、Wan-Sheung Li
DOI:10.1039/b002999h
日期:——
the E-substituted diene selenyl ester 7 underwent sequential cyclisations in the presence of Bu3SnH-AIBN leading to the trans-decalone 8 exclusively, the corresponding Z- and E-isomers of the methoxycarbonyl-substituted diene 16, under similar conditions, gave rise to a 2∶1 mixture of the trans- and cis-decalones 17a and 17b respectively in 62–73% yield. Cyclisation of the triene selenoate 30 led to