Regio- and Stereoselective Preparation of 3-Trimethylsilylallylic Alcohols by Solvolysis of 2-Trimethylsilylic Derivatives of 1-Bromo- and 1,1-Dibromocyclo-propanes in the Presence of CuSO4

The interaction of 1-bromo- and 1,1-dibromocyclopropanes with an equimolar quantity of CuSO₄ in a DMSO–water mixture (molar ratio halocyclopropane:CuSO₄·5H₂O:DMSO:H₂O = 1:1:10–12:14–16) proceeds via cleavage of the three-membered ring to selectively give the most thermodynamically stable isomers of the corresponding 3-trimethylsilyl-substituted allylic or 2-bromoallylic alcohols.