Asymmetric organocatalytic cascade Michael/hemiketalization/retro-Henry reaction of β,γ-unsaturated ketoesters with α-nitroketones.

An unprecedented enantioselective organocatalytic Michael/hemiketalization/retro-Henry cascade sequence is described, which catalyzed by a simple bifunctional indane amine-thiourea catalyst. This process provides a new route to the enantioselective synthesis of 5-nitro-pent-2-enoates, a precursor to α-ketolactam. © The Royal Society of Chemistry 2011