A versatile method for the preparation of 2,2-disubstituted morpholine analogues

We describe a versatile synthetic method for the preparation of 2,2-disubstituted morpholine analogues. Iodoetherification of 1,1-disubstituted olefin with N-Boc-aminoethanol using NIS proceeded smoothly in a regioselective manner and the following cyclization was accomplished in good yield. We successfully applied this method for the preparation of the key intermediate 2 of tachykinin receptor antagonist.