Density 947 kg/m³ | Appearance Colorless liquid | |
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Alpine borane is the commercial name for an organoboron compound that is used in organic synthesis. This reagent is generated by treating 9-BBN with α-pinene to give a sterically crowded trialkylborane. The resulting chiral species can stereoselectively reduce ketones, aldehydes, even deutero aldehydes in what is known as the Midland Alpine Borane Reduction, or simply the Midland Reduction:
C8H12B-pinanyl + RCDO → C8H12BOCHDR + (+)-d-pinene
Hydrolysis of the resulting borinic ester affords the alcohol:
C8H12BOCHDR + H2O → C8H12BOH + HOCHDRIt is also effective for the stereoselective reduction of certain acetylenic ketones.
Related reagents
A range of alkyl-substituted derivatives of borane and diborane are specialty reagents in organic synthesis. Two such reagents that are closely related to Alpine borane are 9-BBN and diisopinocampheylborane.
References
Alpine borane Wikipedia(Text) CC BY-SA