Selective hydrogenation of cyclic polyenes

A hydrogenation process comprising:

• (a) contacting a non-activated ruthenium catalyst with hydrogen, a first cyclic polyene comprising a polyunsaturated olefin having at least 6 carbon atoms and at least 2 ethylenic double bonds, and a first solvent, wherein said first cyclic polyene is present in an amount less than about 50 volume percent and said first solvent is present in an amount greater than 50 volume percent based on the total volume of the components, under hydrogenation conditions to produce an activated ruthenium catalyst and an activation effluent comprising said first solvent and a first cyclic monoene product;
• (b) separating said activated ruthenium catalyst from a major portion of said activation effluent;
• and
• (c) contacting said activated ruthenium catalyst with a second cyclic polyene comprising a polyunsaturated olefin having at least 6 carbon atoms and at least 2 ethylenic double bonds, and
• hydrogen
• under suitable hydrogenation conditions to produce a second cyclic monoene product.