Reduction of Xanteene and the Oxidative Rearrangement of 1,4,5,8-Tetraeydroxanteene to a Spirodiketolactone

Abstract

Xanthene (dibenzopyran) was reduced to the corresponding tetrahydro (2) and dihydro (3) ethers. The electrochemical reduction was monitored to determine the optimum yields. 2 was oxidized to the corresponding syn and anti bis epoxides which cleaved and mged to 7-oxaspiro[5.8]pentadeca-3, 10-dien-1,8,13-trione(6).