Of-
Example of the use of the prefix "Des-" |
Deoxybenzoin (top) contains one less hydroxy group than benzoin (bottom). |
For comparison, the structural formula of benzoin. |
In chemical nomenclature , the prefix Des- , also De- , is used to indicate that a substance is missing something compared to another substance (parent compound). After Des- or De- is indicated what is missing, followed by the designation (= name) of the master connection.
Richard Willstätter also used this notation for the ring opening of a base with the empirical formula unchanged .
Dehydro
If a hydrogen atom is “missing” on two adjacent sp 3 -hybridized carbon atoms compared to the parent compound and the two carbon atoms (now sp 2 -hybridized) are now connected by a C = C double bond, the addition prefix “Dehydro-” is used. If two hydroxyl groups opposite the parent compound become two carbonyl groups , the prefix dehydro- is also used. So z. B. from ascorbic acid (= parent compound) dehydroascorbic acid . Similarly, from cholic the dehydrocholic , a physiologically important bile acid .
Desmethyl
“Desmethyl-” means that a methyl group is “missing” from a parent compound and this has been replaced by a hydrogen atom. The Des carotenoids all methyl groups are missing.
Desmethoxy
“Desmethoxy-” means that a methoxy group is missing from a parent compound and has been replaced by a hydrogen atom.
Deoxy
Deoxysugars are carbohydrates in which a hydroxyl group has been replaced by a hydrogen atom. Deoxyribose (2-deoxy- D- ribose) is of particular importance as an important component of deoxyribonucleic acids ( DNA ). Similarly, in deoxybenzoin, the benzoin hydroxyl group has been replaced by a hydrogen atom.
See also
- Deamination , the cleavage of a primary amino group from chemical compounds, e.g. B. Amino acids
Individual evidence
- ^ A b Wolfgang Holland: The nomenclature in organic chemistry, VEB Deutscher Verlag für Grundstoffindustrie Leipzig, pp. 36–37.
- ^ Philipp Fresenius and Klaus Görlitzer: Organic-chemical nomenclature , Wissenschaftliche Verlagsgesellschaft Stuttgart, 1991, 3rd edition, pp. 136-137, ISBN 3-8047-1167-7 .
- ^ Brockhaus ABC Chemie , VEB FA Brockhaus Verlag Leipzig 1965, p. 277.
- ↑ Philipp Fresenius and Klaus Görlitzer: Organic-chemical nomenclature , Wissenschaftliche Verlagsgesellschaft Stuttgart, 1991, 3rd edition, p. 138, ISBN 3-8047-1167-7 .
- ^ Albert Gossauer: Structure and reactivity of biomolecules , Verlag Helvetica Chimica Acta, Zurich, 2006, p. 332, ISBN 978-3-906390-29-1 .
- ↑ Philipp Fresenius and Klaus Görlitzer: Organic-chemical nomenclature , Wissenschaftliche Verlagsgesellschaft Stuttgart, 1991, 3rd edition, p. 138, ISBN 3-8047-1167-7 .
- ^ Brockhaus ABC Chemie , VEB FA Brockhaus Verlag Leipzig 1965, p. 276.