Tetraallylic, tetraallenic, and tetrapropargylic stannanes (0.25 equiv) react with aldehydes in methanol to provide unsaturated alcohols in good to excellent yields (56-99%). These reactions proceed exclusively with allylic rearrangement for tetra(2-butenyl)tin 2b and tetra(1,2-butadienyl)tin 16c and predominantly with allylic rearrangement for tetrapropadienyltin 16a and tetra(2-butynyl)tin 6e. Allylation reactions also proceeded smoothly with reactive ketones such as ethyl pyruvate (9a) and cyclohexanone (9b). The corresponding TFA-catalyzed reactions of dimethyl acetals 4d and 4e are regiospecific with allylic rearrangement.
Journal of Organic Chemistry Vol. 66, Issue 23, p. 7811-7817