Naphthalenes and Quinolines by Domino Reactions of Morita-Baylis-Hillman Acetates.

An efficient synthetic route to highly functionalized naphthalenes and quinolines has been developed using domino reactions between Morita-Baylis-Hillman (MBH) acetates and active methylene compounds (AMCs) promoted by anhydrous KCO in dry ,-dimethylformamide (DMF) at 23 °C. The substrates incorporate allylic acetates positioned adjacent to a Michael acceptor as well as an aromatic ring activated toward a SAr ring closure. A control experiment indicated that the initial reaction was an S2'-type displacement of a side chain acetoxy by the AMC anion to afford the alkene product bearing the added nucleophile to the SAr aromatic ring acceptor. Thus, equilibration of the alkene geometry of the initial product was required prior to cyclization. Products were isolated in good to excellent yields. Numerous cases (24) are reported, and several mechanistic possibilities are discussed.