Abstract: A process for purifying a crude isoprene containing polymerization inhibiting materials such as acetylenes and sulfur compounds to produce high purity or polymerization grade isoprene comprising distilling the crude isoprene in the presence of at least one member selected from saturated hydrocarbons containing 6 to 8 carbon atoms, withdrawing the polymerization inhibiting materials as an overhead fraction and obtaining purified isoprene as a bottom fraction.

Abstract: A process for producing styrene which comprises subjecting 4-vinylcyclohexene to gas phase catalytic oxidation with a molecular oxygen-containing gas, for example, air, characterized in that the oxidation is carried out by use of a catalyst composition represented by the general formula,Mo.sub.12 Bi.sub.0.1.sub.-10 Fe.sub.0.sub.-15 Co.sub.0.sub.-15 Pb.sub.0.sub.-15 X.sub.0.sub.-10 Y.sub.0.sub.-3 O.sub.nwherein X is at least one element selected from the group consisting of zirconium, cadmium, niobium, and antimony; Y is at least one element selected from the group consisting of lithium, sodium, potassium, rubidium, cesium and thallium; 1.ltoreq.Fe + Co + Pb.ltoreq.25; and n is the number of oxygen atoms sufficient to replenish the valences of other elements. According to the above-mentioned process, styrene can be produced in a high yield.