Conjugate additions of organocuprates to a 3-methylene-6-isopropyldiketopiperazine acceptor for the asymmetric synthesis of homochiral α-amino acids
Bull SD., Davies SG., Garner AC., O'Shea MD.
Addition of a range of organocuprates to (S)-N,N′-bis(p-methoxybenzyl)-3-methylene-6-isopropylpiperazine-2, 5-dione 8 affords cis-3-isopropyl-6-alkyldiketopiperazines in excellent yield and >95% de. Subsequent deprotection and hydrolysis of these cis-3-isopropyl-6-alkyldiketopiperazines affords homochiral (S)-α-amino acids in excellent yield.