[GRAPHICS]Free radical reaction of Vinyl iodides having dinenoate function in the presence of tributyltin hydride or tris(trimethylsilyl)silane caused a sequential cyclization reaction to produce (4 + 1) and (4 + 2) annulated compounds by means of a cascade radical reaction. Stereogenic centers of the cascade reaction were highly controlled. On the contrary, the cathodic electrolysis of the vinyl iodides afforded monocyclic compounds.
STAKEM F. G.; HECK R. F., J. ORG. CHEM., 1980, 45, NO 18, 3584-3593