ChemInform Abstract: Utilization of Sulfide, Sulfoxide, and Sulfone Groups as Regiochemical Control Elements in the Diels‐Alder Reaction of Naphthoquinones.

Abstract

AbstractThe Diels‐Alder reaction of the sulfones (I), which are unsym. substituted by methoxyl groups on the benzenoid ring, with the vinylketene acetals (II) or (V) proceeds regioselectively to give the anthraquinones (III), including the natural products pachybasin (IIIa) and phomarin 6‐methyl ether (IIIb) or the deoxyanthracyclinones (VI) together with minor amounts of the alkyl derivatives (IV) or (VII).