Preferred Label : lactols; 
IUPAC definition : cyclic hemiacetals formed by intramolecular addition of a hydroxy group to an aldehydic
               or ketonic carbonyl group. they are thus 1-oxacy-cycloalkan-2-ols or unsaturated analogues,
               e.g.; 
         
         
            Origin ID : L03438; 
 See also See also
 
         
         
         cyclic hemiacetals formed by intramolecular addition of a hydroxy group to an aldehydic
            or ketonic carbonyl group. they are thus 1-oxacy-cycloalkan-2-ols or unsaturated analogues,
            e.g.