Stereoselective synthesis of functionalised cyclopropanes from nitroalkenes via an organocatalysed Michael-initiated ring-closure approach

Synthetically useful nitrocyclopropanes are easily obtained via Michael addition of dimethyl bromomalonate to nitrostyrenes promoted by commercially available (S)-alpha,alpha-di-beta-naphthlyl-2-pyrrolidinemethanol as the catalyst, followed by DABCO-mediated intramolecular nucleophilic substitution. The functionalised nitrocyclopropanes are obtained in good yield, excellent diastereoselectivity and up to 49% ee. (C) 2010 Elsevier Ltd. All rights reserved.