In
organic chemistry
Organic chemistry is a subdiscipline within chemistry involving the scientific study of the structure, properties, and reactions of organic compounds and organic materials, i.e., matter in its various forms that contain carbon atoms.Clayden, J.; ...
, dihydropyran refers to two
heterocyclic compound
A heterocyclic compound or ring structure is a cyclic compound that has atoms of at least two different elements as members of its ring(s). Heterocyclic chemistry is the branch of organic chemistry dealing with the synthesis, properties, and ...
s with the
formula
In science, a formula is a concise way of expressing information symbolically, as in a mathematical formula or a ''chemical formula''. The informal use of the term ''formula'' in science refers to the general construct of a relationship betwee ...
C
5H
8O:
*
3,4-Dihydro-2''H''-pyran
*3,6-dihydro-2''H''-pyran
Nomenclature
In IUPAC names, "dihydro" refers to the two added hydrogen atoms needed to remove one double bond from the parent compound
pyran
In chemistry, pyran, or oxine, is a six-membered heterocyclic, non-aromatic ring, consisting of five carbon atoms and one oxygen atom and containing two double bonds. The molecular formula is C5H6O. There are two isomers of pyran that differ by the ...
. The numbers in front of the prefix indicate the position of the added hydrogen atoms (and not the position of the double bonds).
The italicized capital ''H'' denotes the "indicated hydrogen", which is a second hydrogen atom present on the location where no double bond is present.
[A Guide to IUPAC Nomenclature of Organic Compounds (Recommendations 1993)]
''R-1.3 Indicated Hydrogen''
/ref>
See also
*Pyran
In chemistry, pyran, or oxine, is a six-membered heterocyclic, non-aromatic ring, consisting of five carbon atoms and one oxygen atom and containing two double bonds. The molecular formula is C5H6O. There are two isomers of pyran that differ by the ...
*Tetrahydropyran
Tetrahydropyran (THP) is the organic compound consisting of a saturated six-membered ring containing five carbon atoms and one oxygen atom. It is named by reference to pyran, which contains two double bonds, and may be produced from it by addin ...
References
{{DEFAULTSORT:Dihydropyran, 2, 3-