Stereoselective synthesis of δ-heteroaryl substituted β-hydroxy-γ,δ-unsaturated α-amino acids
作者:Giuseppe Cremonesi、Piero Dalla Croce、Francesco Fontana、Concetta La Rosa
DOI:10.1016/j.tetasy.2006.09.023
日期:2006.10
Enantiomerically pure 6-heteroaryl substituted beta-hydroxy-gamma, delta-unsaturated alpha-amino acids were stereoselectively synthesized starting from (2R)-(+)-2,5-dihydro-3,6-dimethoxy-2-isopropylpyrazine (Schollkoffs reagent) and suitable beta-heteroaryl-alpha, beta-unsaturated aldehydes. The stereocontrolled addition gave a mixture of two diastereoisomers whose configurations were assigned on the basis of spectroscopic data and the accepted model for aldol condensation of the Schollkoffs reagent. Upon controlled hydrolysis the adducts were transformed into the corresponding methyl esters of 6-heteroaryl substituted beta-hydroxy-gamma,delta-unsaturated alpha-amino acids. (c) 2006 Elsevier Ltd. All rights reserved.