Process for recovering oligomerization product

A process for recovering normal alpha olefins from an oligomerization reaction product obtained by contacting ethylene under oligomerization conditions with a nickel ylide defined by the following formula:

• ##STR77## wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.6, R.sub.7 and R.sub.8 are either alike or different members selected from the group consisting of hydrogen, alkyl radicals having from about one to about 24 carbon atoms, aryl radicals having from about six to about 20 carbon atoms, alkenyl radicals having from about two to about 30 carbon atoms, cycloalkyl radicals having from about three to about 40 carbon atoms, aralkyl and alkaryl radicals having from about six to about 40 carbon atoms, halogen radicals, hydroxyl, alkoxy and aryloxy groups, and hydrocarbyl groups carrying halogen, hydroxyl, alkoxy or aryloxy groups, provided that at least one of each of R.sub.1 to R.sub.8 radicals is a sulfonato group or an alkyl, aryl, alkenyl, cycloalkyl, aralkyl or alkaryl carrying a sulfonato group, M is sulfur or oxygen, E is phosphorus, arsenic, antimony or nitrogen and F is phosphorus, arsenic or antimony, which comprises contacting said reaction product with ammonium hydroxide to obtain a product composed of two layers, an upper layer containing normal alpha olefins and a lower layer containing nickel ylide residue, and then separating said layers from each other to recover the desired normal alpha olefins.