PHASE-TRANSFER-CATALYZED REACTIONS BETWEEN POLYSULFIDE ANIONS AND ALPHA,BETA-UNSATURATED CARBONYL-COMPOUNDS

Ammonium polysulfide reacts with alpha,beta-unsaturated ketones and aldehydes under PTC (phase transfer catalysis) conditions in a rather different manner than it does in homogeneous systems. 1,3-Diphenyl-2-propen-1-one (chalcone, 1) and 4-phenyl-3-buten-2-one (benzylideneacetone, 3) give sulfur-linked dimers (mainly disulfides). 3-Phenyl-2-propen-1-al (cinnamaldehyde) polymerizes. 1,5-Diphenyl-1,4-pentadien-3-one (dibenzylideneacetone, 7) gives the known six-membered ring thianones and new seven-membered ring 1,2-dithiepanones 9 along with a polymer. Carvone gives a disulfide dimer that converts to a mixture of bicyclic sulfur-containing compounds. Sodium polysulfide is much less effective because of the base-induced decomposition of either the products or the intermediates. Sodium sulfide reacts in the same manner as it does in homogenous systems.