A chiral synthetic route to the amino esters 5 and 6, which contain the fundamental framework of ent-imbricatine (ent-3), has been developed as a prelude to the total synthesis of the starfish alkaloid imbricatine (3). The route started from the sulfur-containing L- phenylalanine derivative 7 and proceeded through key steps such as cyclization fo the amide 8 without racemization, reduction to the 1, 3-cis-tetrahydroisoquinoline 9, and ...
