The kinetic resolution of racemic 5-alkoxy-2 (5H)-furanones, using a chiral aminoalcohol catalyzed 1, 4-addition of arylthiols, was examined. Using various butenolides it was shown that a γ-alkoxy substituent appears to be essential to reach high enantioselectivities whereas electron-donating substituents in the arylthiols also increase the selectivity. Cinchona alkaloids are the preferred catalysts for the kinetic resolution, with quinine and ...
