Synthesis of polyfunctionalized vinyl cyclopropanes via the Nal-catalyzed ring-opening cyclization of doubly activated cyclopropenes with 1,1-bis(phenylsulfonyl)ethylene

A Nal-catalyzed reaction of 3,3-bis(alkoxycarbonyl)cyclopropenes in the presence of 1,1-bis(phenylsulfonyl)ethylene providing an efficient route to a series Of polyfunctionalized vinyl cyclopropanes is described. The reaction is general for a range of different 3,3-bis(alkoxycarbonyl)cyclopropenes affording the products in moderate to high yields. A plausible rationale for this transformation is discussed. (C) 2009 Elsevier Ltd. All rights reserved.