Anhydrous

In chemical nomenclature, the prefix anhydro- is used to indicate that intramolecular water has been split off from a parent compound and that its name is to be added accordingly.

Anhydrous

Anhydro tetracycline with the blue marked C = C double bond, which results from the elimination of water from tetracycline.

Comparison: structural formula of the parent compound tetracycline

Ether

If water is split off intramolecularly from a parent compound at two hydroxyl groups and an ether oxygen atom remains, the addition prefix “anhydro” is used to describe it. An example is the formation of an oxirane ( epoxy ), e.g. B. 2,3-Anhydro-4-O-methyl-α- D -mannopyranose, an anhydro sugar (sugar anhydride). This definition for the prefix “Anhydro-” also exists in IUPAC rule C-44.1.

Alkenes

When intramolecular water is split off from an alkanol (alcohol, parent compound) and an alkene is formed, the subtraction prefix “Anhydro-” is used to describe it. An example is anhydrotetracycline, which is derived by name from the parent compound tetracycline . This definition for the prefix “Anhydro-” does not correspond to the IUPAC rules.

Individual evidence

1. ↑ ^{a b} Philipp Fresenius and Klaus Görlitzer: Organic-chemical nomenclature , Wissenschaftliche Verlagsgesellschaft Stuttgart, 1991, 3rd edition, p. 139, ISBN 3-8047-1167-7 .
2. ↑ Otto-Albrecht Neumüller (Ed.): Römpps Chemie-Lexikon. Volume 1: A-Cl. 8th revised and expanded edition. Franckh'sche Verlagshandlung, Stuttgart 1979, ISBN 3-440-04511-0 , p. 209.