Iodine-induced cyclizations of n-alkoxyaminoalkenes.a stereocontrolled approach to TRANS-2,6-disubstituted piperidine alkaloids

摘要

Iodine-induced intramolecular cyclizations of gamma-alkenyl-N-alkoxyamines preferentially produce 2,6-trans-disubstituted piperidines.Subsequent iodoetherifications of N-benzyloxypiperidines demonstrate the stereoselective transfer of oxygen to a proximate carbon via formation of bicyclic 1,3-syn-isoxazolidines.The strategy facilitates preparation of nonracemic piperidine diols from acyclic,optically active alcohols.