Upon treatment with Me2TiCl2 or Me3Al in the presence of TiCl4, an H atom at the olefinic 4-position is replaced by a Me group. Terminal homoallyl alcs. afford E isomers. If the double bond is internal, the C chain (at the other side of the OH group) gives up its original position to the entering Me group and switches to the other one at the same C atom. [on SciFinder (R)]