Reduction of Cyclopropanecarboxylic Acids by Borane, a Chemoselective Reduction Sensitive to Steric Interactions and Reaction Conditions

A number of cyclopropanecarboxylic acids have been reduced by BH 3 reagents in THF to the corresponding cyclopropyl alcohols; the yield is sensitive to the steric influence of the substituents attached to the ring, the reaction temperature, and the nature of the borane reagent.