anhydrogalactoses
Anhydrogalactoses are a group of carbohydrate derivatives formed by the removal of a molecule of water from galactose. Galactose is a monosaccharide, a simple sugar. When two galactose units undergo dehydration, they can form a disaccharide with an anhydro linkage. More commonly, anhydrogalactoses refer to the cyclic forms of galactose that result from intramolecular dehydration. These can occur in solution or during certain chemical reactions.
One prominent example is levoglucosan, which is technically an anhydroglucose, but the concept applies to galactose