The Highly Enantiocontrolled Functionalization of a 2-Oxazolone Heterocycle by Intramolecular Radical-Based Addition. A Chiral Synthon for 2-Amino Alcohols which Contain Three Contiguous Stereocenters.

Abstract The intramolecular Ru(II)-catalyzed radical addition of the 2,2-dichloroacyl pendant group to the 2-oxazolone moiety followed by reductive dechlorination with (TMS)3SiH provides an effective tool for the formation of the chiral 2-amino alcohol synthon in a completely regio- and stereocontrolled manner. The prepared synthon is useful in the preparation of isomers of unusual amino hydroxy acids including the key component of bleomycins.