A Regioselective, One-Pot, Transition-Metal-Free α-Alkylation of Quinone Monoacetals for Various Organic Transformations

Regioselective reactions of biologically significant quinones are challenging. An unprecedented advancement in quinone monoacetal (QMA) chemistry is proposed for constructing regioselective and less explored α-alkylated QMAs through the Morita-Baylis-Hillman (MBH) reaction. Electrophilic QMAs were transformed to nucleophilic umpolung reagents for aldol-type condensation with several electrophiles. Mechanistic studies reveal that solvent (TFE:water (1:1)) and in situ-generated potassium acetate accelerate the reaction. The ensuing MBH adducts were scalable and underwent several post-synthetic transformations and late-stage functionalization.