Abstract: Grignard reagents of halo-substituted conjugated dienes are prepared by reaction of 1- or 2-halo-substituted conjugated diene with magnesium metal employing a metal halide/saturated aliphatic halide catalyst system. The Grignard reagent can be employed in the preparation of hydroxy-substituted conjugated dienes and hydroxy-substituted allenes. Adjustment of the molar ratio of the metal halide to the halo-substituted conjugated diene permits favoring of hydroxy-substituted conjugated dienes or hydroxy-substituted allenes in the diene products.

Abstract: An olefinic hydrocarbon is isomerized utilizing a catalyst system consisting essentially of a mixture of a nickel complex of the formula (R.sub.3 P).sub.2 NiX.sub.2 and an alkali metal borohydride.