Preparation of enol lactones of 3,5,7-triketo and 3,5,7,9-tetraketo acids by the condensation of 4,6-dimethoxy-2-pyrone with anions of mono- and diketones

Abstract

Condensation of the anions of acetone, acetophenone, acetylacetone and benzoylacetone with 4,6-dimethoxy-2-pyrone afforded good yields of the corresponding 6 substituted 4-methoxy-2-pyrones which were converted to the 4-hydroxy analogs by demethylation with iodotrimethylsilane.