A Diels–Alder approach to functionalized cis-hydroisoquinolines. Attempts to prepare a tricyclic core unit of manzamine A

Abstract

A dihydropyridinone 8 has been synthesized and shown to undergo efficient Lewis-acid mediated Diels–Alder cycloadditions leading to functionalized cis-hydroisoquinoline products such as 11, 13 and 14. Additional manipulations of both the dienophile 8 and a silyl enol ether cycloadduct 12 are also described, along with attempts to apply the cycloaddition route to the synthesis of a tricyclic manzamine A intermediate.