What is meant by hydroboration-oxidation reaction ? Illustrate it with an example.

Explanation

The addition of diborane to alkenes to form trilkylboranes followed by their oxidation with alkaline hydrogen peroxide to form alcohols is called hydroboration-oxidation. For example,
`underset("Propene")(CH_(3)CH=CH_(2))+underset("Diborane")((BH_(3))_(2))underset("ether")overset("Dry")to CH_(3)-underset(H)underset(|)(C)H-underset(BH_(3))underset(|)(C)H_(2) overset(CH_(3)CH=CH_(2))to (CH_(3)CH_(2)CH_(2))_(2)B-H overset(CH_(3)CH=CH_(2))to underset("Tri-n-propylborane")((CH_(3)CH_(2)CH_(2))B)`
`underset("Tri-n-propylborane")((CH_(3)CH_(2)CH_(2))_(3)B)+3H_(2)O_(2) overset(OH^(-)//H_(2)O)to underset("Propan-1-ol")(3CH_(3)CH_(2)CH_(2)OH)+underset("Boric acid")(B(OH)_(3))`
The alcohols obtained by this process appear to have been formed by direct addition of water to the alkene contrary to the Markovnikov's rule.