Regioselective Alkylation of the Polyfunctional Nucleophile 1-(methylthio)-3-Triethylsilyloxypentadienyllithium

Article abstract of DOI:10.1002/hlca.19810640706

γ-Selective sulfenylation of the triethylsilyloxypentadienyllithium 1 gave the versatile alkylthiodiene 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.