A simple synthesis of 4-substituted 2-(3-hydroxy-2-oxo-1-phenethyl- propylcarbamoyl)pyrrolidine-1-carboxylic acid benzyl esters as novel cysteine protease inhibitors

Abstract

A convenient synthesis of 4-substituted 2-(3-hydroxy-2-oxo-1- phenethylpropylcarbamoyl)pyrrolidine-1-carboxylic acid benzyl esters 17 and 18 as new cysteine protease inhibitors is described. The synthetic key strategies involve the diazocarbonyl insertion reaction of N-Boc-L-homophenylalanine (1) by diazomethane, acetylation of the bromoketone 2 with sodium acetate, and condensation of acids 12, 14 with (3S)-3-amino-2-oxo-5-phenyl-pentyl acetate monohydrochloride (4) in good yield. © 2008 Verlag der Zeitschrift für Naturforschung.