Abstract
Octamethyl ether of product A which was derived from ustilaginoidin A by alkaline degradation was synthesized by the Ullmann condensation of dimethyl ether of 5-bromo-6, 8-dimethyl-1, 3-naphthalenediol (XXI). Starting from 3, 5-dimethoxyphenylacetic acid (IX), the 2-bromo derivative (VII) was prepared which was C-acetylated to afford XX, and then cyclized to form a bromonaphthalene derivative (XXI), whose methyl ether is XXII. The position of C-C linkage connecting two monomeric moieties of ustilaginoidins has unequivocally been established. Rearrangement of bromine atom during the process of methylation of bromohydroxynaphthalenes and cyclization forming the naphthalene nucleus were also discussed.
