Convenient syntheses of 3-aryl-3,4-dihydroisocoumarins

摘要

A convenient method for the synthesis of naturally occurring 3,4-dihydroisocoumarins by judicious use of Friedel-Craft acylation, regioselective formylation and oxidative cyclisation reactions is described. O-methylated analogues of montroumarin and thunberginols C and D and have been synthesised using 3,5-dimethoxyphenylacetic acid as a starting material. Furthermore, the starting material 3,5-dimethoxyphenylacetic acid was synthesised by a route involving an oxidative Nef reaction.