Selective Hydrolysis of Thioacetals with Thallium(III) Nitrate

In connection with research at present being pursued in these laboratories we required quantities of thioacetal ( 1 ) for study. Reaction of Wieland-Miescher ketone ( 2 ) with one equivalent of 1,2-ethanedithiol gave only ( 3 ) resulting from reaction at the α,β-unsaturated carbonyl group. The structure for ( 3 ) was deduced primarily from C n. m. r. which showed a saturated carbonyl absorption (δ212.6) 1 . The preferential reaction of 1,2-ethanedithiol with α,β-unsaturated ketone