Abstract Cis lithium enethiolates, generated from substituted dithioesters, undergo 1, 4- addition uith vapious β-monosubstituted α-unsaturated ketones. With acyclic enones one of the tw resulting diastereomeric 5-oxodithioesters is predominantly formed (ratio up to 95: 5). Its anti configuration was proven by chemical correlation in one case. Evidence for fhe stereospecificity of this Michael, addition is given.
