Abstract
Acyl groups are transferred from diverse N- and O-acyl derivatives of chiral 3.5-bis-(1-hydroxyethyl)-[ 1,2,4]-triazole to amino acid esters enantioselectively, with 7% to 68% ee. depending on the temperature conditions and nature of the reagents Thionyl chloride replaced the hydroxyl groups of (S)-1-[4-amino5-((S)- 1-hydroxy-ethyl)-[1,2,4]-triazol-3-yl]-ethanol 3 stereospecifically with inversion, as confirmed by X-ray analysis, which also revealed unusual crystal structures with asymmetric units comprising three molecules of 4-amino-3,5-bis(R-1-chloroethyl)-1,2,4-triazole 5 and four of 3,5-bis((R)-1-chloroethyl)-1H-1,2,4-triazole 6. (c) 2010 Elsevier Ltd All rights reserved