(5R)-7,8:9,10-Di-O-isopropylidene-2,6-dioxa-4-azaspiro[4,5]decan-3-one: a new chiral spirooxazolidin-2-one derived from D-(+)-galactose for use in asymmetric transformations
Abstract
Starting from D-(+)-galactose, the crystalline spirooxazolidin-2-one 2 can be readily prepared in an optically pure state by a nitrene-mediated four-step sequence, and serves to control both aldol and Diels–Alder reactions with high chiral efficiency, being easy to remove after use.