Stereoselective synthesis of versatile 2-chloromercurium-3,5-syn-dihydroxy esters via intramolecular oxymercuration

Regio- and stereocontrolled alkoxy mercuration of α,β-unsaturated esters allows direct access to 1,3-syn diols in good yields. Demercuration of adducts leads to 1,3 skipped dihydroxy esters, alcohols, and α-halo esters. The deprotection of acetonide with Amberlyst 15 on 1,3-syn-dihydroxy esters gives the corresponding δ-lactones.