Novel enantioselective synthesis of trans-α-(2-carboxycyclo-prop-1- yl)glycines: Conformationally constrained L-glutamate analogues

1998-03-27
Demir, Ayhan Sıtkı
Tanyeli, Cihangir
CAGİR, Ali
Nawaz Tahir, M.
Ulku, Dincer
D- and L-alpha-(2-carboxycycloprop-1-yl)glycines were synthesized from trans-1,3-di(2-furyl)propenane. Conversion of the double bond to a cyclopropane is followed by-the formation of an oxime ether. Enantioselective reduction of the oxime ether, separation of diastereomers and oxidation of the furane rings gave enantiomerically pure D- and L-CCG I and CCG II. The structure of oxime 7b was determined by X-ray crystal structure analysis. The key step is the oxazaborolidine catalyzed enantioselective conversion of oxime ethers to amines. (C) 1998 Published by Elsevier Science Ltd. All rights reserved.