A Convenient Enantiospecific Route towards Bioactive Merosesquiterpenes by Cationic‐Resin‐Promoted Friedel–Crafts Alkylation with α,β‐Enones

Abstract

Abstract An enantiospecific route towards bioactive merosesquiterpenes, based on the cationic‐resin‐promoted Friedel–Crafts alkylation of alkoxyarenes with an α,β‐unsaturated ketone, is reported. Reaction of ketone 11 with 3,4‐methylenedioxyphenol afforded the corresponding chromene. Treatment of 11 with protected phenol 20 gave aryl nordrimane ketone 21 , a suitable intermediate in the synthesis of bioactive merosesquiterpenes and their 8‐epi derivatives. By utilizing this methodology, a formal synthesis of (+)‐puupehenone and other related metabolites, via triflate 25 , is described. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)