text: Some alcohols are reduced to alkanes when treated with hydrosilanes in the presence of a strong Lewis acid. Brønsted acids may also be used. Tertiary alcohols undergo facile reduction using boron trifluoride etherate as the Lewis acid. Primary alcohols require an excess of the silane, a stronger Lewis acid, and long reaction times.
  Skeletal rearrangements are sometimes induced. Another side reaction is nucleophilic attack of the conjugate base on the intermediate carbocation. In organosilane reductions of substrates bearing prostereogenic groups, diastereoselectivity is often high. Reduction of either diastereomer of 2-phenyl-2-norbornanol leads exclusively to  the endo diastereomer of 2-phenylnorbornane. None of the exo diastereomer was observed.
  Allylic alcohols may be deoxygenated in the presence of tertiary alcohols when ethereal lithium perchlorate is employed as a source of Li.
  Reductions of alkyl halides and triflates gives poorer yields in general than reductions of alcohols. A Lewis or Bronsted acid is required.