Abstract Unsaturated thiols having the system-C= C-SH can be obtained by cleavage of the corresponding alkyl sulfides-C= C-SR with alkali metals in liquid ammonia and acid hydrolysis after evaporation of the ammonia. Cycloalkanone dimethyl dithioacetals (CH 2) n C (SCH 3) 2 give cycloalkanethiols (CH 2) n C (H)(SH)(n= 2, 4, 5, 6) on treatment with 4 equivalents of alkali metal. Alkyl cycloalkyl sulfides (CH 2) n C (H)(SR)(R= CH 3 or C 2 H ...