A new synthesis of enatiomerically pure α- and β-amino acid derivatives based on the chemistry of aziridinyl anions.

Abstract

Optically active sulfinylaziridines having 4-methoxyphenyl group on their nitrogen atom were synthesized from optically active 1-chloroalkyl p-tolyl sulfoxide and an imine, which was derived from benzaldehyde and p-anisidine, stereoselectively in good overall yields. The sulfinylaziridines were treated with ethylmagnesium bromide or tert-butyllithium to afford the aziridinylmagnesiums or aziridinyllithiums, respectively, in quantitative yields. Cross-coupling of the aziridinylmagnesiums with iodoalkanes in the presence of Cu(I) iodide gave tetra-substituted aziridines in high yields; from which enantiomerically pure β,β-disubstituted β-amino acid derivatives were synthesized. On the other hand, from the aziridinyllithium, enantiomerically pure quaternary phenylalanine and quaternary aspartic acid derivatives were synthesized.