Griseofulvin

Griseofulvin is active against dermatophytes and is used as an antimycotic agent in dermatology. The molecular formula of griseofulvin was C17H17ClO6. Regarding the O-atoms, griseofulvin was found to be neutral. It, therefore, does not contain a COOH group. Griseofulvin could not be acetylated; hence, it does not have a free OH group. Griseofulvin formed a mono-oxime, indicating the presence of a C═O group. Upon hydrolysis with 1N H2SO4 in aqueous EtOH, griseofulvin was cleaved to griseofulvic acid with the loss of one CH3O group. This had initially been considered to indicate that griseofulvin is a methyl ester. Isogriseofulvin was as well obtained from griseofulvin by treatment with methanolic HCl. Finally, basic hydrolysis of isogriseofulvin regenerated griseofulvic acid. This behavior of griseofulvic acid is typical of an unsymmetrical β-diketoneunit. Accordingly, griseofulvin would not be a methyl ester but rather a vinylogous ester.