1.A study was made of the telomerization of ethylene with acetic acid in presence of dicyclohexyl peroxydicarbonate at 60‡.2.In the telomerization not only straight-chain acids are formed, but also 2-ethylhexanoic and 2-butylhexanoic acids. The yields of these acids are reduced considerably by lowering of the reaction temperature from 140 to 60‡.3.In the telomerization of ethylene with acetonitrile in presence of t-butyl peroxide at 140‡ not only straightchain nitriles are formed, but also 2-ethylhexanenitrile and 2-butylhexanenitrile.4.The formation of acids and nitriles with branched chains is to be explained by a scheme which includes the 1,5-migration of hydrogen in the intermediately formed ra