152375-59-2

Upstream product

• 2835-06-5 phenylglycin 
• 77290-52-9 N-benzyliden-2-phenylglycine ethyl ester 
• 72651-17-3 phenylglycine ethyl ester hydrochloride 
• 193421-73-7 α-allylphenylglycine ethyl ester 
• 193421-72-6 2-Phenyl-2-{[1-phenyl-meth-(E)-ylidene]-amino}-pent-4-enoic acid ethyl ester 

Downstream Products

• 193421-75-9 (R)-2-tert-Butoxycarbonylamino-2-phenyl-pent-4-enoic acid ethyl ester 
• 193421-77-1 (R)-2-tert-Butoxycarbonylamino-5-hydroxy-2-phenyl-pentanoic acid ethyl ester 
• 193421-76-0 (R)-2-Benzyloxycarbonylamino-5-hydroxy-2-phenyl-pentanoic acid ethyl ester 
• 193421-74-8 (R)-2-Benzyloxycarbonylamino-2-phenyl-pent-4-enoic 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.

Enzymatic resolution of α,α-disubstituted α-amino acid esters and amides

The scope and limitations of the enzymatic resolution of α,α-disubstituted α-amino acid amides by an amino acid amidase from Mycobacterium neoaurum and of the corresponding ethyl esters with Pig liver esterase (PLE) have been studied. Moderate enantiomeric excesses were obtained with PLE, with only a narrow substrate specificity. Mycobacterium neoaurum on the contrary yields a broad range of S-α,α-disubstituted α-amino acids 1 and the corresponding R-amides 2.