Peroxotungstic acid and quaternary ammonium peroxotungstic salts when complexed to organophosphorus(V) ligands exhibit enhanced reactivity and selectivity in the epoxidation of unsaturated alcohols with hydrogen peroxide. The organophosphorusligands contain the phosphoryl OP subunit as complexing moiety and are related to phosphine oxide, arylphosphonic acid and acidic phosphate ester. Allylic and