188822-65-3

Upstream product

• 84049-31-0 (2R,4S)-3-aza-2-methyl-4-phenyl-ethylpentanoate 
• 79-04-9 chloroacetyl chloride 
• 2627-86-3 (S)-1-phenyl-ethylamine 
• 535-11-5 Ethyl 2-bromopropionate 

Downstream Products

• 188822-67-5 (6R,1'S)-1-(1'-phenethyl)-6-methyl-piperazine-2,5-dione 
• 188822-75-5 (3S,6R)-3-Benzyl-5-ethoxy-6-methyl-1-((S)-1-phenyl-ethyl)-3,6-dihydro-1H-pyrazin-2-one 
• 188822-71-1 (3S,6R)-5-Ethoxy-6-methyl-3-(3-methyl-but-2-enyl)-1-((S)-1-phenyl-ethyl)-3,6-dihydro-1H-pyrazin-2-one 
• 188822-69-7 (6R,1'S)-5-ethoxy-6-methyl-1-(1'-phenethyl)-3,6-dihydro-1H-pyrazine-2-one 
• 188822-97-1 (3S,6R)-3-Benzyl-5-ethoxy-6-methyl-3,6-dihydro-1H-pyrazin-2-one 
• 188823-13-4 (2R,5S)-2-methyl-5-acetamido-3-aza-4-oxo-6-phenyl-ethyl hexanoate 

Relevant academic research and scientific papers

Stereoselective synthesis of dipeptides - I

The alkylation of 7 occurs in moderate to good trans stereoselection (d.e.40-98%), while a poorer d.e. (40-98%) is observed for 8. On the contrary, in both substrates the alkylation with CH3I produces a greater amount of the cis isomer (d.e.48%).). Cleavage of the lactims 9(a,e) gives enantiomerically pure dipeptides 14(a,e). The absolute configuration of the introduced stereogenic centres has been assigned on the basis of the 1H-NMR data in connection with the conformational analysis.