Synthesis of the four stereoisomers of cyclobutane analogues of phenylalanine in enantiomerically pure form
摘要:
All stereoisomers of 1-amino-2-phenylcyclobutanecarboxylic acid-c(4)Phe-have been synthesized and the series c(n)Phe has thus been completed. The use of two different strategies based on a cyclization reaction, starting from ethyl isocyanoacetate and dialkyl malonate, respectively, gave both cis-c(4)Phe and trans-c(4)Phe in racemic form. HPLC resolution of one of the intermediates using a cellulose-derived chiral stationary phase allowed the isolation of the corresponding enantiomerically pure N-protected amino acids, prepared for incorporation into peptides. The relative stereochemistry of enantiopure compounds has been unambiguously assigned. (c) 2005 Elsevier Ltd. All rights reserved.
Synthesis of the four stereoisomers of cyclobutane analogues of phenylalanine in enantiomerically pure form
摘要:
All stereoisomers of 1-amino-2-phenylcyclobutanecarboxylic acid-c(4)Phe-have been synthesized and the series c(n)Phe has thus been completed. The use of two different strategies based on a cyclization reaction, starting from ethyl isocyanoacetate and dialkyl malonate, respectively, gave both cis-c(4)Phe and trans-c(4)Phe in racemic form. HPLC resolution of one of the intermediates using a cellulose-derived chiral stationary phase allowed the isolation of the corresponding enantiomerically pure N-protected amino acids, prepared for incorporation into peptides. The relative stereochemistry of enantiopure compounds has been unambiguously assigned. (c) 2005 Elsevier Ltd. All rights reserved.