The kinetic features of thermal degradation of the adduct of hydrogen peroxide and acetone in monocarboxylic acids and aliphatic alcohols were studied. This peroxide was tested as a radical initiator of ethylene telomerization by isobutyric acid and ethanol. The initiator was shown to enable the selective telomerization of ethylene at moderate temperatures (40-100degreesC) with a high yield of the desired product.