STEREO-DIVERGENT SYNTHESIS OF L-THREO-[2,3-H-2(2)]AMINO AND L-ERYTHRO-[2,3-H-2(2)]AMINO ACIDS USING OPTICALLY-ACTIVE DIOXOPIPERAZINE AS A CHIRAL TEMPLATE

A stereo-divergent synthesis of L-three-and L-erythro-[2,3-H-2(2)]amin o acids from the same chiral auxiliary is described. Aldolization of N ,N'-di(tert-butoxycarbonyl)dioxopiperazine 2, derived from L-valine, w ith various aldehydes followed by successive elaboration gives various 2,3-dehydroamino acid derivatives. Catalytic deuteriation of the deri vatives then followed by acidic hydrolysis affords L-[2,3-H-2(2)]amino acids in good yields with high optical purities, It becomes clear tha t diastereoselective deuteriation for either the three or the erythro isomer depends upon the protective groups on the nitrogen atoms in the dioxopiperazine ring.