stereoselective routes towards isopropenylcyclopropanes have been devised. Secondary cis-isopropenylcyclopropylcarbinols have been obtained either by regio- and stereoselective hydroxy-directed cyclopropanation of the corresponding dienols or from bicyclic cyclopropyl lactones derived from intramolecularcyclopropanation of allylicdiazoacetates. Contrary to previous reports, base-induced 1,3-elimination of γ-epoxy