Extension to the Silyl-Tethered Radical Cyclization: Cyclohex-2-en-1-oxy Vinyl Silanes in Stereoselective Radical Addition/Cyclization Cascades.

A novel radical cascade reaction of xanthates with 1-[(vinyldimethylsilyl)oxy]cyclohex-2-enes is developed. Due to the steric and electronic differentiation of the two olefinic functions, exclusive regioselectivity and high stereoselectivity of the addition-cyclization are observed. Several methods for modification of both the silicon tether and the xanthate function are reported.