Heterocyclic compounds

Summary

4-Isopropyl-1: 2-α-naphthapyrone is hydrolysed by dilute alkali to 1-hydroxy-2-naphthoic acid. It is further observed that 6-bromo- and 6-acetyl-4-isopropyl-1: 2-α-naphthapyrones are also hydrolysed to 4-bromo-and 4-acetyl-1-hydroxy-2-naphthoic acids. As the hydrolysis of the coumarins too-hydroxy carboxylic acids is unusual, these cases provide interesting exceptions to the usual behaviour.