Boron-to-oxygen migration

The R—O—B bonds are hydrolyzed in the alkaline aqueous solution, generating the alcohol. The oxidation mechanism involves a series of boron-to-oxygen migrations of the alkyl groups. The stereochemical outcome is replacement of the C—B bond by a C—O bond with retention of configuration. In combination with the stereospecific syn hydroboration, this allows the structure and stereochemistry of the alcohols to be predicted with confidence. The preference for hydroboration at the less substituted carbon of a double bond results in the alcohol being formed with regiochemistry that is complementary to that observed for direct hydration or oxymercuration. 

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