266694-07-9

Upstream product

• 1027465-24-2 [(2R,3S)-4-(1-Hydroxy-3-phenyl-propyl)-5-oxo-2-phenyl-tetrahydro-furan-3-yl]-carbamic acid tert-butyl ester 
• 152580-54-6 (3S,4R)-3-tert-butoxycarbonylamino-4-phenyl-4-butanolide 
• 177839-75-7 ((4S,5R)-2-Oxo-5-phenyl-oxazolidin-4-yl)-acetic acid 
• 178897-35-3 (4S,5R)-4-methoxycarbonylmethyl-5-phenyloxazolidin-2-one 
• 177839-63-3 (4S,5R)-4-hydroxyethyl-5-phenyloxazolidin-2-one 
• 266694-08-0 (S)-2-benzyloxycarbonylamino-4-tert-butyldimethylsilyloxy-1-phenylbutan-1-one 
• 266694-24-0 (3S,4R)-3-tert-butoxycarbonylamino-4-phenyl-2-(phenylpropylidene)-4-butanolide 

Relevant academic research and scientific papers

Stereoselective synthesis of β-benzyl-α-alkyl-β-amino acids from l-aspartic acid

A stereoselective synthesis of β-benzyl-α-alkyl-β-amino acids 1 and 2 from L-aspartic acid 3 has been developed. Methyl 5-phenyloxazolidin-2-one-4-acetate 4 was prepared from L-aspartic acid 3 through the acylation of benzene or phenyllithium with a-amino carboxyl group of L-aspartic acid skeleton. Alkylation of a dianion of 4 with alkyl halides and subsequent hydrogenation afforded cmfi-disubstituted /J-amino acids Ib and le in high stereoselectivities. Complete reversal of the stereoselection was realized by the alkylation of 4-phenyl-3-feri-butoxycarbonylamino-4-butanolide 6 which was obtained in a single step from 4. The 2,3,4-trisubstituted amino lactone 7 thus obtained was hydrogenated to give a syra-disubstituted β-amino acid 2a. The syn-products 2b, 2c, and 2d were alternatively prepared via aldol condensation of 6 with aromatic or aliphatic aldehydes followed by stereoselective reduction of the double bond with nickel chloride-sodium borohydride.