Stereospecific synthesis of trifluoromethyl-substituted polyfunctionalized cyclopropanes

Treatment of methyl (Z)-2-bromo-4,4,4-trifluoro-2-butenoate 1 with active methylene compounds 2 in the presence of NaH as base affords a stereospecific synthetic route to trifluoromethyl substituted cycloproparies in good yields. (C) 2004 Elsevier Ltd. All rights reserved.