SYNTHESIS OF CF3-CONTAINING SULFUR HETEROCYCLES - THE FIRST STABLE 2-THIETANOL DERIVATIVE

The reaction of a,P-unsaturated CF3-containing ketones R(1)R(2)C=CHCOC F3 1-4 with ammonium hydrosulfide was investigated. The structure of t he enones was shown to influence the reaction path, and the correspond ing six-membered sulfur heterocycles bearing trifluoromethyl groups, 5 -8, or mercaptan, 9, were obtained. The reaction of 3-adamantylidene-1 ,1,1-trifluoropropan-2-one,3, results in the corresponding four-member ed heterocycle 8, which has a stable 2-thietanol fragment. The oxidati on of sulfides 5-8 by hydrogen peroxide yields sulfones 10-12 or 1,3-s ultine 13 (in the case of 8). Product stereochemistry and reaction mec hanism are discussed.