Sequential combination of Michael and acetalization reactions: Direct catalytic asymmetric synthesis of functionalized 4-nitromethyl-chromans as drug intermediates

Abstract

Functionalized chiral 4-nitromethyl-chromans as drug intermediates were achieved for the first time through sequential combination of Michael and acetalization reactions on 2-(2-nitro-vinyl)-phenols with acetone and alcohols in the presence of a catalytic amount of 9-amino-9-deoxyepiquinine and Ph 2CHCO2H followed by p-TSA. © 2010 The Royal Society of Chemistry.