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.

An organocatalytic domino annulation approach C(sp)-OMe cleavage to unlock the synthesis of pyranochromenones enabled by HFIP.

Fused pyranochromenone derivatives have extensive applications in medicinal chemistry. Herein, we report the first HFIP/TsOH catalyzed, one-pot domino reaction by cleavage of the C(sp)-OMe bond. Control experiments reveal that 1,3,5-trimethoxybenzene is rapidly protonated in the presence of HFIP to yield a dearomatized cationic diene intermediate.