Toshihiko Kimura

Regioselective mono-addition of lithium enolates to N-carbamoyl-L-pyroglutamates

Abstract Regioselective mono-addition of lithium enolate of esters to N-carbamoyl-L-pyroglutamates ( 1 ) gave excellent yields of ( 2S )-5-oxoamino acid derivatives ( 2 ) which were found to be an effective synthon for syntheses of carbapenams and carbapenems.

Chirospecific synthesis of (+)-PS-5 from L-glutamic acid

(+)-PS-5 p-nitrobenzyl (PNB) ester (1a) has been synthesized from N-Cbz-L-pyroglutamate (2a). The key reactions were the reductive pyrrolidine ring formation from the 5-oxoamino acid derivative (3) and stereo-differential protonation at C-6 of the dienolate derived from the carbapenam (4).

Chirospecific synthesis of amino acids and analogues

Proline and its analogues demonstrate a wide range of biological activity, inview of that we have synthesized amino acid analogues having pyrrolidine ring starting from Af-carbamoylpyroglutamate (1). In this process we have established regio-selective mono-addition reaction, stereospecific substitution at C-4 and pyrrolidine ring formation.