Oxidation of Boranes to Alcohols

Perhaps the most utilized transformation of organoboranes is their oxidation to alcohols, accomplished with basic hydrogen peroxide (H2O2, NaOH). The active reagent is the hydroperoxide anion (HOO ). Alkenes are converted to alcohols with a Markovnikov orientation (the OH group is on the more substituted carbon of the C=C moiety) of the OH group via either acid catalyzed addition of water or oxymercuration (sec. 2,10.A,B). 

This alcohol-forming hydrohoration reaction figures prominently in many natural product syntheses. It is facile and highly regioselective, and sometimes diastereoselective.94 in a synthesis of a usneoidol E analog, Dfez et al. reacted 117 with a borane-THF complex, which led to incorporation of the OH group on the less 

Cyclic boranes can also be used to generate alcohols in a chain extension reaction. The length of the chain is controlled by the ring size of the borinane. B-Methoxyborinane (128a) reacted with 1-lithio-l-octyne to 

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