Solid-phase aldol condensations mediated by zinc acetate and 2,2′-bipyridine under weakly basic conditions

A new, efficient and convenient method for the synthesis of resin-bound α,β-unsaturated ketones is described. Reaction of polystyrene-linked benzaldehydes with methyl ketones or tetralone in the presence of zinc acetate, 2,2′-bipyridine and an amidine base at elevated temperature gave resin-bound (E)-enones in high purity. These were transformed into thioethers by reaction with thiophenol.