Hydrolysis of (Z)-2-alkoxy-3-arylpropenals as a short-cut to benzylglyoxals

Hydrolysis of the C=C bond in 2-alkoxy-3-aryl(hetaryl)-propenals, depending upon substituents in the molecule, can proceed according to Markovnikov or Michael rule or with heterolytic opening of the cycle (in the case of 2-alkoxy-3-furylpropenal). Hydrolysis of 3-phenyl substituted alkoxypropenals bearing electron-withdrawing substituents (Cl, NO₂) in the p-position has allowed a method for the preparation of corresponding benzylglyoxals (stable in enol form) to be developed.