An alkene reacts with diborane/THF to produce an alkyl borane. Oxidation and hydrolysis of the alkyl borane with hydrogen peroxide and base yield alcohol. Hydroboration R=2−methylcyclopentyl Oxidation
In the first step, boron and hydrogen undergo syn addition to the alkene; in the second step, treatment with hydrogen peroxide and base replaces the boron with −OH with retention of configuration. The net addition of −H and −OH occurs with anti-Markovnikov regioselectivity and syn stereoselectivity.
