SYNTHESIS AND LEWIS ACID ASSISTED REARRANGEMENT OF NOVEL DONOR-ACCEPTOR SUBSTITUTED CYCLOPROPANES - HIGHLY STEREOSELECTIVE [4+1] ANNULATION APPROACH TO SUBSTITUTED AND SPIRO CYCLOPENTENE DERIVATIVES

摘要

The cyclopropanes 2a-h having 4-(bismethylthio)butadienyl moiety as donor group, which are easily obtained by regioselective cyclopropanation of vinylogous ketene dithioacetals 1a-h with oxodimethylsulphonium methylide, undergo facile Lewis acid assisted vinylcyclopropyl rearrangement to afford substituted and spiro cyclopentenes 3a-h in good yields. Copyright (C) 1996 Published by Elsevier Science Ltd [References: 31]