Studies Culminating in the Total Synthesis and Determination of the Absolute Configuration of (-)-Saudin

Tetrahedron. 2011 Dec 23;67(51):9787-9808. doi: 10.1016/j.tet.2011.09.067. Epub 2011 Sep 21.

Abstract

A full account of studies that culminated in the total synthesis of both antipodes and the assignment of its absolute configuration of Saudin, a hypoglycemic natural product. Two approaches are described, the first proceeding though bicyclic lactone intermediates and related second monocyclic esters. The former was obtained via asymmetric Diels-Alder cycloaddition and the latter by an asymmetric annulation protocol. Both approaches employ a Lewis acid promoted Claisen rearrangement, with the successful approach taking advantage of bidentate chelation to control the facial selectivity of the key Claisen rearrangement.