Organocatalytic asymmetric nitrocyclopropanation of α,β-unsaturated aldehydes

A novel organocatalytic highly enantioselective nitrocyclopropanation reaction of alpha,beta-unsaturated aldehydes is presented. The 1-nitro-2-formylcyclopropane derivatives synthesized from this catalytic transformation were converted to the corresponding beta-nitromethyl-acid esters, which are excellent precursors of GABA analogues such as Baclofen, by subsequent organocatalytic chemoselective ring-opening. (C) 2008 Elsevier Ltd. All rights reserved.