Coordinative Role of Alkali Cations in Organic Reactions. IV. Benzoylation, Phenacylation, and Benzylation of Kojic Acid

Article abstract of DOI:10.1246/bcsj.53.569

Using kojic acid (5-hydroxy-2-hydroxymethyl-4-pyrone) as a substrate, the title reactions were carried out with various alkali metal hydroxides.Whereas phenacylation (with KOH or NaOH) and benzylation (with KOH, NaOH, or LiOH) are possible only on the phenolic hydroxyl, benzoylation can be carried out selectively as well as collectively on both the hydroxyl group (in 80percent aq.EtOH).The results were discussed in terms of the interactive role of alkali cations with the substrate.