Anthraquinone is readily reduced to the hydroquinone (9, 10-anthracenediol), which under basic conditions serves as a reactive diene for cyloaddition purposes. Catalytic hydrogenation in pyridine solvent provides convenient access to this species, and efficient reactions occur with dienophiles in situ, provided that they are sufficiently reactive. Thus N- methylmaleimide (NMM) gives the bicyclic bridgehead diol in near quantitative yield when ...
