193421-75-9

Upstream product

• 193421-72-6 2-Phenyl-2-{[1-phenyl-meth-(E)-ylidene]-amino}-pent-4-enoic acid ethyl ester 
• 2835-06-5 phenylglycin 
• 77290-52-9 N-benzyliden-2-phenylglycine ethyl ester 
• 72651-17-3 phenylglycine ethyl ester hydrochloride 
• 24424-99-5 di-tert-butyl dicarbonate 
• 152375-59-2 (R)-α-allyl-α-phenylglycine ethyl ester 

Downstream Products

• 193421-77-1 (R)-2-tert-Butoxycarbonylamino-5-hydroxy-2-phenyl-pentanoic acid ethyl ester 

Relevant academic research and scientific papers

A convenient synthesis of protected (R)-α-phenylproline derivatives using the Mitsunobu reaction

Boc-(R)-α-phenylproline ethyl ester 1 was prepared in good yield starting from racemic phenylglycine. Condensation of phenylglycine ethyl ester with benzaldehyde furnished N-benzylidene phenylglycine ethyl ester which was allylated under phase transfer catalysis conditions. After acidic hydrolysis, tile resulting α-allylphenylglycine ethyl ester was enzymatically resolved using PLE. Hydroboration and oxidation of the double bond, Boc-protection and subsequent ring closure using the Mitsunobu reaction protocol gave rise to Boc-(R)-α-phenylproline ethyl ester.