An enantioselective synthesis of (R)-4-piperidinylglycine

Abstract An efficient process for the synthesis of ( R )- N - t -Boc-4-piperidinylglycine 8a , an unnatural amino acid, via enantioselective rhodium-catalyzed hydrogenation of the Cbz-enamide 5a is described. Subsequent deprotection of 8a affords unprotected ( R )-4-piperidinylglycine 9 in good yield.