Stereoselective 1,4-Addition of Primary Alcohols to γ-Alkoxy-α,β-unsaturated Esters

The scope and limitations of the diastereoselective 1,4-addition reaction of primary alcohols to γ-alkoxy-α,β-unsaturated esters were investigated. We found that a variety of sodium alkoxides, generated from the corresponding primary alcohols with NaH, underwent 1,4-addition reactions with (E)-enoates in CH2Cl2 at –23 °C to give β-alkoxy esters in modest yields with good to excellent syn-selectivity, whereas stereoselectivity was not observed with the use of glycerol derivatives as nucleophiles. Cyclic acetal protection was found to play a pivotal role for the reaction to proceed.