REACTION OF TRIMETHYLSILYL ENOL ETHERS WITH ISOQUINOLINIUM SALTS. A FACILE SYNTHESIS OF ETHYL 1-(2-OXOALKYL)-1,2-DIHYDROISOQUINOLINE-2-CARBOXYLATES AND THEIR CYCLIZATION
An efficient method is described for the synthesis of ethyl 1-(2-oxoalkyl)-1,2-dihydroisoquinoline-2-carboxylates by C–C bond formation between 2-ethoxycarbonylisoquinolinium chloride and trimethylsilyl enol ethers. The products were treated with a few bases to afford the corresponding pyrido [2,1-a] isoquinoline derivatives.