Brown hydroboration/oxidation, synthetic

The synthetic method used to accomplish this is an indirect one known as hydroboration-oxidation. It was developed by Professor Herbert C. Brown and his coworkers at Purdue University in the 1950s as part of a broad progran designed to apply boron-containing reagents to organic chemical synthesis. The number of applications is so large (hydroboration-oxidation is just one of them) and the work so novel that Brown was a corecipient of the 1979 Nobel Prize in chemistry. 

Hydroboration is defined as the addition of borane or one of its derivatives to a multiple bond. It is an enormously versatile reaction synthetically, developed by H.C. Brown in the 1950s and recognized by his Nobel Prize in 1979. We will be looking specifically at the use of a hydroboration-oxidation sequence to accomplish the stereo- and regiospecific anti-Markovnikov addition of water to alkenes. 

The work of H. C. Brown has made hydroboration an enormously useful synthetic reaction. Oxidation of the adduct with alkaline hydrogen peroxide removes the boron smoothly without rearrangement and replaces it by a hydroxy group. The oxidation proceeds entirely with retention of configuration. For example, the product of Reaction 7.19 is converted by oxidation to trans-2-methylcyclopentanol in high yields (Equation 7.20). 

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