Abstract: n-Valeraldehyde is produced by hydroformylation of butene-1 in the presence of one or more of cis- and trans-butene-2 and iso-butylene using a rhodium complex catalyst such as HRh(CO)PPh.sub.3).sub.3. Reaction conditions include use of at least about 100 moles of free triorganophosphine per gram atom of rhodium, a temperature of about 80.degree. C. to about 130.degree. C., a total pressure of not more than about 50 kg/cm.sup.2 absolute, a partial pressure of carbon monoxide of not more than about 1.5 kg/cm.sup.2 absolute, and a partial pressure of hydrogen of from about 1.0 to about 7.5 kg/cm.sup.2 absolute. An n-/iso-ratio of 20:1 and a conversion efficiency of butene-1 to n-valeraldehyde of over 85% are possible under these conditions with essentially no resin formation despite the presence of iso-butylene. The n-/iso-valeraldehyde mixture can be aldolized and reduced without intermediate purification to give a commercially acceptable C.sub.10 -plasticizer alcohol.

Abstract: A rhodium-catalyzed hydroformylation process in disclosed in which an overhead vapor stream is recovered from the hydroformylation zone containing reactant alkene, hydrogen, carbon monoxide, alkene hydrogenation product(s), aldehyde product and aldehyde condensation products. This vapor stream is subjected to condensation conditions in one or two stages to condense therefrom condensible components comprising unreacted alkene, aldehyde product, and aldehyde condensation products. Non-condensed components of the vapor stream (e.g. H.sub.2 and CO) are recycled to the hydroformylation zone. Unreacted alkene is also recycled in liquid form to the hydroformylation zone.

Abstract: A hydroformylation process is disclosed utilizing a rhodium complex catalyst and an excess of a triorganophosphine wherein active rhodium catalyst and triorganophosphine can be separated from inactive rhodium, "heavies" and triorganophosphine oxide in partially deactivated reaction medium by extraction into concentrated phosphoric acid or aqueous solutions containing at least 40% by weight phosphoric acid. By neutralization of the phosphoric acid extract in the presence of organic solvent, e.g. aldehyde trimers, a solution of active rhodium catalyst and triorganophosphine can be produced that is suitable for re-use in the hydroformylation reaction.