Stereoselective synthesis of geometrically strained, oxindole-appended vinyl cyclopropanes and highly substituted cyclopentenes via sulfur ylide cyclopropanation and vinyl cyclopropane rearrangement

Abstract

An efficient diastereoselective synthesis of oxindoleappended vinyl cyclopropanes from bromo isomerised Morita Baylis-Hill man adducts of isatin with activated alkylidene and isatilidines via sulfur ylide cyclopropanation reaction have been achieved.The synthesised vinyl cyclopropanes have undergone vinyl cyclopropane rearrangement and [3+2) cyclo addition with an allene to afford dispiro bisoxindole bridged by cyclopentene and spirocyciopentene-2-oxindole-bridged spirocyclopropane-2-oxindole derivatives respectively.