Reaction of 1,4-bis(trimethylsilyl)-2-butene with aromatic aldehydes catalyzed by TiCl4: an approach to (1-vinylallyl)benzene type derivatives

1,4-bis(Trimethylsilyl)-2-butene 1 can react with alkyl and aromatic aldehydes in the presence of titanium tetrachloride to give α-(trimethylsilyl)methyl homoallylic alcohols and (1-vinylallyl)benzene type compounds in poor to good yield according to the related position of each substituents present on the aromatic ring. In the last case, the reaction involves a SE 2 ′ type electrophilic substitution of 1,4-bis(trimethylsilyl)-2-butene by aromatic aldehydes activated by TiCl4, followed by a 1,2-migration of a vinyl group.