Synthesis of isochromene esters utilizing 1,6-addition of nucleophiles to benzopyranylidenetungsten(0) complexes

Org Lett. 2006 Mar 16;8(6):1077-9. doi: 10.1021/ol052951t.

Abstract

[reaction: see text] A concise method for the preparation of isochromene carboxylates has been developed by the regioselective 1,6-addition of various nucleophiles such as Grignard reagents, alkoxide, and cyanide onto benzopyranylidenetungsten(0) complexes, followed by iodine oxidation of the addition intermediates.