The application of vinylogous iminium salt derivatives to efficient formal syntheses of the marine akaloids lamellarin G trimethyl ether and ningalin B

Tetrahedron. 2009 May 30;65(22):4283-4292. doi: 10.1016/j.tet.2009.03.085.

Abstract

Studies directed at the synthesis of lamellarin G trimethyl ether and ningalin B via vinylogous iminium salt derivatives are described. The successful strategy relies on the formation of a 2,4-disubstituted pyrrole or a 1,2,3,4-tetrasubstituted pyrrole from a vinylogous iminium salt or vinylogous iminium salt derivative. Subsequent transformations of these highly substituted pyrroles lead to efficient and regiocontrolled formal syntheses of the respective pyrrole containing natural products.