Synthesis of novel tetracyclo-isocoumarins via AcOH-catalyzed cascade reaction of heterocyclic ketene aminals with 2,2-dihydroxy-2H-indene-1,3-dione

A facile synthesis of tetracyclo-isocoumarins based on the AcOH-catalyzed cyclocondensation and rearrangement reaction between heterocyclic ketene aminals and 2,2-dihydroxy-2H-indene-1,3-dione is described. This method provides direct access to tetacyclo-isocoumarins, a class of compounds with potential broad spectrum biological activities. (C) 2010 Elsevier Ltd. All rights reserved.