NEW GENERAL SYNTHESIS OF MEDIUM RING-LACTONES VIA A REGIOSELECTIVE β-SCISSION OF ALKOXYL RADICALS GENERATED FROM CATACONDENSED LACTOLS

Article abstract of DOI:10.1016/S0040-4020(01)81628-8

We describe a new general method for the synthesis of medium-sized lactones based on ring-enlargement via a regioselective β-scission of alkoxyl radicals generated by photolysis from the hypoiodites of several catacondensed lactols.The syntheses of 9-membered lactones from 6/5 fused lactols, 10-menbered lactones including a naturally occuring lactone, phoracantholide I, from 6/6 or 7/5 fused lactols, and 11-membered lactones from 7/6 or 8/5 fused lactols are shown to be achieved by the present method.This new method may have a potential for application to the synthesis of either smaller or larger-sized lactones.