HYDROZIRCONATION OF ALKENYLOXIRANE DERIVATIVES - PREPARATION OF CYCLOALKYLMETHANOLS

Cyclopentyl and cyclopropylmethanol derivatives were efficiently prepa red through a chemoselective hydrozirconation reaction of (1-butenyl)o xirane and vinyloxirane with Cp2ZrHCl. However, the attemped reaction of (1-pentenyl)oxirane or (1-propenyl)oxirane failed to yield cyclohex yl or cyclobutylmethanols. The ring formation was stereospecific and p roceeded with the inversion of the configuration at the reacting oxira ne carbon. The origin of stereospecificity and the stereoselectivity i n the formation of cyclopropylmethanols was presumed by the approach o f the Schwartz reagent from the less hindered site of the stable gauch e-conformer of the vinyloxirane compound in the transition state. (Cyc lopropylmethyl)amine derivatives were also prepared by the treatment o f vinylaziridine derivatives with Cp2ZrHCl. (C) 1997 Elsevier Science Ltd. All rights reserved.