Here, 21 mole of B2H6 react with alkene by
Markownikoff's addition and form trialkyl Borone called Hydroboration, H2O2/OH−gives oxidation. So, trialky borone oxidise in alcohols and reaction is also called Hydroboration-oxidation. 3R−CH=CH2B2H6′B′(R−CH2−CH2)3−B H2O2/H+3R−CH2−CH2−OH