The asymmetric conjugate addition of medium order alkyl cuprate reagents. R 5Cu 3Li 2, to 2-cyclohexen-1-one. 2-cyclopenten-1-one and 2-cyctohepten-1-one, with the help of phosphorus ligand B *, is described. 3-Alkyl substituted cyclohexanones are obtained in essentially optically pure form. The same chiral ligand, associated with CuI, in catalylic amount (10%), allows the asymmetric conjugate addition of Et 2Zn to 2-cyclohexen-1-one.