A simple and effective method for the reduction of acyl substituted heterocyclic 1,3-dicarbonyl compounds to alkyl derivatives by zinc - acetic acid - hydrochloric acid

Article abstract of DOI:10.1016/0040-4020(95)00733-O

3-Acyl-4-hydroxy-2(1H)-quinolones (1a-k) were reduced in good yields (66-97%) to 3-alkyl-4-hydroxy-2(1H)-quinolinones (2a-k) using zinc powder (particle size 〈45 μm) in acetic acid/hydrochloric acid. This method could be transformed to 3-acetyl-4-hydroxy-