162780-30-5

Upstream product

• 100-52-7 benzaldehyde 
• 90891-21-7 L-(+)-α-amino-4-phenylbutyric acid ethyl ester hydrochloride 
• 244277-48-3 ethyl (R)-(-)-2-hydroxy-4-oxo-4-phenylbutanoate 
• 88330-79-4 ethyl-(Z)-2-hydroxy-4-oxo-4-phenyl-but-2-enoate 
• 90315-82-5 ethyl (R)-2-hydroxy-4-phenylbutyrate 

Downstream Products

• 1161828-76-7 N-benzyl-N-methyl-L-homophenylalanine ethyl ester 
• 46460-23-5 ethyl 2-amino-4-phenyl-(2S)-butyrate 

Relevant academic research and scientific papers

Ethyl 2,4-dioxo-4-phenylbutyrate: A versatile intermediate for the large-scale preparation of enantiomerically pure α-hydroxy and α-amino acid esters

Starting from ethyl 2,4-dioxo-4-phenylbutyrate, both enantiomers of six enantiomerically pure α-hydroxy and α-amino acid esters (homophenylalanine derivatives) were prepared on >100 g scale. The key step involves a Pt-cinchona catalyzed enantioselective hydrogenation followed by enrichment via crystallization. All derivatives are commercially available.

'N-stereogenic quaternary ammonium salts' from L-amino acids: Synthesis, separation, and absolute configuration

Diastereoisomeric linear and cyclic 'N-chiral quaternary ammonium salts' (QASs) were efficiently synthesized from corresponding L-amino acids in high yields. The diastereoisomers of each pair of 'N-chiral QASs' were successfully separated. The absolute configurations of these QASs were determined predominately by X-ray single-crystal analysis. The 1H-NMR data of 'N-chiral QASs' provided characteristic information on the configuration of the N-chiral center. 'N-Chiral QASs' exemplified by [N(R)]-2a and [N(S)]-2a are stable in protic and aprotic solvents within a broad pH and temperature range.