Abstract The synthesis of epoxides 3a–r is achieved in excellent yields by reaction of the α, β- unsaturated ketones 1a–c, 4, 4′-disubstituted (E)-chalcones 1d–o, and 2′-hydroxy-4- substituted (E)-chalcones 1p–r with isolated dimethyldioxirane (2a)(as acetone solution) and/or in situ generated ethyl (methyl) dioxirane (2b). This method constitutes a useful alternative to the Weitz-Scheffer epoxidation (alkaline H 2 O 2) of such electronpoor ...
