| Abstract: | γ-Selective sulfenylation of the triethysilyloxypentadienyllithium 1 gave the versatile alkylthiodene 4 which on successive deprotonation and alkylation furnished with high regioselectivity the γ-products 6 . Fluoride-promoted silylether cleavage 6 → 7 may be followed by intramolecular 4 + 2]-addition 7c → 8 and sulfoxide elimination 8 → 9 . The conversions 7b → 12 and 7a → 17 demonstrate the feasibility of 5 to serve as an equivalent of the hypothetical β-deprotonated divinylketone 13 whose two enone units may be unmasked separately. |
