The open form of D-glucose (and many other sugars) can cyclize to form hemiacetals.
Under acidic conditions the hemiacetal form of glucose can react with other alcohols to give acetals known as glycosides. These are widely distributed in nature.
When a hemiacetal joins with an alcohol with the elimination of a water molecule, an acetal is formed.
eg. monosaccharides can be converted to glycosides by treatment with alcohols.