Selective oxidation of terminal isopropyl groups to the correspoding tertiary alcohols by an electrochemical method is described. Under the conditions using the Tl (TFA) 3- hematoporphyrin-O2-cathodic reduction system, several substrates such as cholesterol (1) and Grundmann's alcohol (3) gave the corresponding tertiary alcohols 2 and 4, respectively, in reasonable yield.