Naturally occurring dibenzofurans. Part 9. A convenient synthesis of phthalides: the synthesis of methyl di-O-methylporphyrilate
Abstract
A convenient synthesis of phthalides [isobenzofuran-1(3H)-ones] from o-halogenobenzyl alcohols is described. This method is then applied to the synthesis of methyl di-O-methylporphyrilate (methyl 1,3-dihydro-4,10-dimethoxy-8-methyl-3-oxoisobenzofuro[5,4-b]benzofuran-7-carboxylate)(2), a derivative of the lichen dibenzofuran porphyrilic acid (1).