Reactivity of unsaturated sultones synthesized from unsaturated alcohols by ring-closing metathesis. Application to the racemic synthesis of the originally proposed structure of mycothiazole

Unsaturated sultones have been synthesized from various primary or secondary alkenols by ring-closing metathesis of the corresponding unsaturated sulfonates. By treatment with a strong base, β,γ-unsaturated sultones can be metalated and subsequently alkylated with electrophiles. When iodomethylmagnesium chloride was selected as the electrophile, seven-membered ring β,γ-unsaturated sultones were converted into homoallylic conjugated (Z)-dienols. This methodology was applied to the racemic synthesis of the originally proposed structure of the marine natural product mycothiazole.