2-halo-3-hydroxy esters 1 or O-acetylated 1,1-dihaloalkan-2-ols 4 is achieved with samarium in the presence of diiodomethane, yielding α,β-unsaturated esters 2 or vinyl halides 5, respectively. The β-elimination reaction was promoted by samarium diiodide, which was generated in situ. The starting halohydrins 1 or 4 are easily prepared by reaction of the corresponding lithium enolates of α-halo esters or dihalomethyllithium