Alkoxydienylstannanes via metalation of alpha,beta-unsaturated and alpha-phenyl acetals: preparation and synthetic uses in the Stille cross-coupling reaction

Treatment of alpha,beta -unsaturated (1 and 2) and alpha -phenyl (3) acetal s with an equimolar mixture of butyllithium and potassium tert-butoxide (Sc hlosser's reagent LIC-KOR) gives alpha -metalated 1,3-dienes and vinyl ethe rs that readily react with chlorotributyltin affording (Z)- functionalized alkoxyvinylstannanes 4-6. Stille cross-coupling reaction between these reac tants and allyl bromide, iodobenzene, or benzoyl chloride produces derivati ves 7-13 that can be moreover converted into carbonyl compounds 14-19 accor ding to an umpolung approach.