Diastereoselective Addition of Chlorotitanium Enolate of <i>N</i>-Acyl Thiazolidinethione to <i>O</i>-Methyl Oximes: A Novel, Stereoselective Synthesis of α,β-Disubstituted β-Amino Carbonyl Compounds via Chiral Auxiliary Mediated Azetine Formation

We have discovered a novel and highly diastereoselective synthesis of azetinyl thiazolidine-2-thiones that utilizes additions of the chlorotitanium enolates of N-acyl thiazolidin-2-thiones to O-methyl aldoximes. The “anti” azetines can be subsequently converted to the corresponding α,β-disubstituted β-amino carbonyl compound with retention of stereochemistry. The formation of azetine and the product of its “hydrolytic” opening has been confirmed by X-ray crystallographic analyses.