A Novel Approach to Functionalized (E)‐1,4‐Diaryl‐1‐butenes by Heck Reaction and Their Applications for the Construction of Dibenzylbutyrolactone Lignan Skeletons by Radical Cyclization.

Abstract

Polyphenylalkene derivatives Q 0740 A Novel Approach to Functionalized (E)-1,4-Diaryl-1-butenes by Heck Reaction and Their Applications for the Construction of Dibenzylbutyrolactone LignanSkeletons by Radical Cyclization. -Terminal olefins, generated in situ by protodesilylation of a mixture of silanols (I) and disiloxanes (II), undergo Pd-catalyzed regioand stereoselective Heck reaction with aryl iodides to give the (E)-butenes (IV) in good yield. The utility of these products is demonstrated by conversion of (IVc) to the lignans (VI)/(VII) and (IX)/(X). -(SINGH, R.; SINGH, G. C.; GHOSH*, S. K.; Tetrahedron Lett. 46 (2005) 28, 4719-4722; Bio-Org. Div., Bhabha At. Res. Cent., Mumbai 400 085, India; Eng.) -Mais 43-107