The C=O groups in open chain forms
of carbohydrates can be reduced to alcohols by sodium borohydride,
NaBH4, or catalytic hydrogenation (H2, Ni, EtOH/H2O).
The products are known as "alditols"
LiAlH4 is usually not suitable because of its incompatibility
with the polar solvents.
Aldehydes, i.e. aldoses, are reduced to primary alcohols.
Ketones, i.e. ketoses, are reduced to secondary alcohols.
