ENANTIOSELECTIVE CYCLOPROPANATION OF ALLYLIC ALCOHOLS WITH DIOXABOROLANE LIGANDS - SCOPE AND SYNTHETIC APPLICATIONS

A very effective chiral controller has been found for the conversion o f allylic alcohols into the corresponding enantiomerically enriched cy clopropanes using bis(iodomethyl)zinc. A variety of chiral, nonracemic cyclopropylmethanols could be obtained according to this method. This methodology was extended with success to the cyclopropanation of unco njugated and conjugated polyenes and homoallylic alcohols. The cyclopr opanation of allylic carbamates has also been investigated with this s ystem, but it was found that enantioenriched cyclopropylmethylamines a re best prepared from enantioenriched cyclopropylmethanols.