A short, versatile chemical synthesis of L- and D-amino acids stereoselectively labelled solely in the beta position.
L- and D-Amino acids which are stereoselectively labelled solely either in the 3-pro-R or in the 3-pro-S-positions have been prepared by a relatively short chemical synthesis in ee of 81 to 86%. This involves Sharpless' aminohydroxylation and cyclisation with inversion of stereochemistry at C-2 to give the stereoselectively labelled D- and L-aziridines and 10a and 10b, and 8a and 8b. These have previously been modified and cleaved with inversion of stereochemistry at C-3 using a number of nucleophiles to give a large variety of protected amino acids. Synthesis of the labelled D- and L-beta-chloroalanines 22a and 22b and 25a and 25b is described here.
Lowpetch
Kreingkrai
K
Department of Chemistry, University of Sussex, Falmer, Brighton, UK BN1 9QJ.
Young
Douglas W
DW