Application of the Buchwald protocol to the coupling of o-bromobenzoates and 1-tetralones directly affords benzodihydronaphthopyrones with a fused tetracyclic system. Aromatization of the 7, 8-dimethoxy-2, 3-methylenedioxy derivative yielded arnottin I, whereas oxidation with dioxirane afforded dihydroarnottin II composed of a spiro phthalide-tetralone system. Sharpless asymmetric dihydroxylation using AD-mix yielded optically active ...
