Total Synthesis of (−)-Cassine

Abstract
The PdCl2-catalyzed cyclization of amino allylic alcohol 16 gave the cyclized product 17a with excellent diastereoselectivity. The versatility of compound 17a as the building block for synthesizing cis-2,6-disubstituted piperidine alkaloids has been demonstrated by a total synthesis of (−)-cassine (1).