Highly stereoselective addition of Grignard reagents to C-cyclopropylnitrone via the bisected s-trans conformation. An efficient synthesis of PEDC, apotent NMDA receptor antagonist having a cyclopropane structure

An efficient synthesis of PEDC (1), a potent NMDA receptor antagonist of a cyclopropane structure, was achieved. The highly stereoselective addition r eaction of MeMgBr to C-cyclopropylnitrone 2, via its bisected s-trans confo rmation which can be predicted from the stereo-electronic effects, was deve loped as the key step. The s-trans conformation predominant in C-cyclopropy nitrone 2 was suggested by NOE experiments. (C) 2000 Elsevier Science Ltd. All rights reserved.