The reaction of isobutylene hydroxycarbonylation with carbon monoxide and an alcohol (ethanol, 1-menthol) in the presence of the palladium acetylacetonate-triphenylphosphine-p-toluenesulfonic acid catalytic system was investigated. It was shown that the reaction proceeds regioselectively with the formation of linear products (ethyl isovalerate, 1-menthyl isovalerate). The optimum conditions for running the process were found, at which the yield of the main products is 67-79%.