Pyrones VII. An Efficient Preparation and the Selective Reduction of Methyl 2,6-Dimethyl-4H-Pyran-4-one-3-Carboxylate

Abstract

The syntheses of 4H-pyran-4-one-3-carboxylic acids and derivatives which have been previously reported (for example, starting with ketene¹, diketene², or dehydroacetic acid³) normally proceed only in low yield, often requiring rigorous control of the reaction conditions. We have shown that the reaction of dehydroacetic acid (1) with “magic methyl” (methyl fluorosulfonate) produces methyl 2,6-dimethyl-4H-pyran-4-one-3-carboxylate (4) in high yield (85%) under mild conditions.