Michael Addition of Thioacetic Acid to α, β-Unsaturated Carboxylic Acid Esters in the Presence of Clays or Zeolites

Abstract

The Michael addition of thioacetic acid to α, β-unsaturated carboxylic acid esters in the presence of clays or zeolites was carried out. Using clays for adding thioacetic acid to di-l-menthylfumarate (1), reactivity and stereoselectivity were found to differ according to the clay, clay pretreatment temperature and solvent, though with no systematic tendency. For S- (-) -2-methyl-1-butyl cinnamate (3) addition in the presence of zeolites of large pore size, adduct stereoselectivity was much greater. The reaction would thus appear to proceed in the cavities of the zeolites.