Borane using alkaline hydrogen peroxide

This new reaction has been used to prepare optically active iodides such as (R)-2-iodobutane (equation I) with inversion of the C—B bond. Note that reaction of this borane with alkaline hydrogen peroxide gives (S)-2-butanol. 

The dialkenylchloroboranes undergo the usual reactions of vinylic boranes, e.g., protonolysis with acetic acid gives olefins, oxidation with alkaline hydrogen peroxide provides the corresponding carbonyl compounds. However, the most useful reactions of these compounds are their ready conversion to the stereochemically pure (E, Z)-1,3-dienes by the Zweifel reaction with I2-NaOH 37>107.108> and into the symmetrical (E,E)- 1,3-dienes, 09 0), mono-olefins 1U) and 1,4-dienes (Chart 10). 

Borane, which is used as a complex with tetrahydrofuran [992] or dimethyl sulfide [611, 992] or generated in situ from lithium borohydride with boron trifluoride etherate [646] or sodium borohydride with aluminum chloride [184], reacts with 3 mol of an alkene to form a tertiary borane. The oxidation with alkaline hydrogen peroxide [183, 992, 1201] or with trimethylamine oxide [991, 992] yields an alcohol (equations 598 and 599). 

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