An efficient asymmetric synthesis of substituted β-alkoxycarbonyl sulfonates is described. Enantiopure α-substituted β-alkoxycarbonyl sulfonates can be obtained via α-alkylation of metalated sulfonates bearing 1,2:5,6-di-O-isopropylidene-α-d-allofuranose as the chiral auxiliary with alkyl bromoacetates. α,β-Disubstituted β-alkoxycarbonyl sulfonates were prepared starting from the corresponding enantiopure γ-nitro sulfonates by using TFA for the cleavage of the chiral auxiliary and causing a simultaneous Meyer reaction.
asymmetric synthesis - sulfonates - esters - alkylation - sugar auxiliary
