Diastereoselective ultrasonically induced zinc-copper conjugate addition to chiral α,β-unsaturated carbonyl systems in aqueous media.

The diastereoselective ultrasonically induced zinc–copper 1,4-addition of alkyl iodides to chiral α,β-unsaturated systems in aqueous media is reported. The reaction of a methylenedioxolanone with a variety of alkyl iodides takes place in good yields and with high diastereomeric excess. The 1,4-addition to (Z)-and (E)-γ,δ-dioxolanyl-a,b-unsaturated esters also proceeds with good yields: the Z-isomer gives good diastereoselectivities while the reactions with the E-isomer are non-stereoselective.