Synthesis of Isotopically Labeled (E)-β,γ-Unsaturated Esters with Total or High Diastereoselectivity by Using Samarium Diiodide.

A simple, efficient, highly diastereoselective method for preparing (E)-α,δ-dideuterio-β,γ-unsaturated esters: SmI2 -promoted reduction/elimination of α-halo-β-hydroxy-γ,δ-unsaturated esters in the presence of D2 O. This provides the desired products in which the C-C double bond is generated with total or high diastereoselectivity.