A simple methodology for the synthesis of 3,4-dihydroisocoumarins

Abstract

In our studies' on the total synthesis of fredericamycin A, an antitumour antibiotic, it was desirable for us to have 1-hydroxyisochroman for building a model spiro-(4,4)-nonane system present in fredericamycin A. The most convenient approach to synthesize 1-hydroxyisochromans is by a suitable hydride reduction of the corresponding 3,4-dihydro-isocoumarins. However, most of the literature methods described for the synthesis of 3,4-dihydron L isocoumarins are quite lengthy and tedious. We describe, herein, a simple and convenient approach for the synttesis of substituted dihydroisocoumarins. This method is of general utility.