cis-2-Alkylcyclohexanols are obtained stereoselectively upon irradiation of a mixture of cyclohexene and the corresponding trialkylborane in the presence of p-xylene as a sensitizer and upon the successive oxidation of the photolysate with alkaline H2O2. The similar reaction of 1-ethylcyclohexene yields 2, 2-dialkylcyclohexanols. Cycloheptene also reacts with the boranes to afford cis-2-alkylcycloheptanols. These reactions are explained ...