SYNTHESIS AND CONFORMATIONAL FEATURES OF TOPOGRAPHICALLY CONSTRAINED DESIGNER CHIMERIC AMINO ACIDS - THE BETA-ISOPROPYL PHENYLALANINES

摘要

All four optically pure isomers of the highly conformationally constrained novel chimeric amino acid, beta-isopropylphenylalanine or beta-phenylleucine, were asymmetrically synthesized in five to six steps in 20-25% overall yield. Computer-assisted molecular modeling revealed that the beta-isopropyl group in these chimeric amino acids plays the dominant role in determining the most favorable side chain conformations. (C) 1997 Elsevier Science Ltd. [References: 32]