There are many reagents that are useful for the reduction of various carbonyl compounds. The complex hydrides NaBH4 and LiAlH4 are among the most useful reagents available for the conversion of carbonyl compounds to alcohols. Sodium borohydride is the less reactive of the two; for example, esters and acids are not affected. Sodium borohydride is very convenient to use, since reactions can be carried out in aqueous or alcoholic solutions. The reduction of bicyclic ketones such as camphor andnorcamphor with these hydrides is quite stereoselective, with one of the two diastereomeric alcohols being formed in over nine times the amount of the other.