The mixed cuprates, generated by reductive lithiation of bis (phenylthio) acetals using lithium 4, 4′-di-tert-butylbiphenylide (LDBB), followed by addition of cuprous bromide- dimethyl sulfide complex, undergo conjugate addition to enones in the presence of trimethylsilyl chloride to produce γ-(phenylthio) ketones. Protection of the ketone as its dioxolane, and reductive lithiation with LDBB provides carbonyl-protected γ-lithioketones. ...
