An oxo-Diels–Alder reaction (also called an oxa-Diels–Alder reaction) is an
organic reaction
Organic reactions are chemical reactions involving organic compounds. The basic organic chemistry reaction types are addition reactions, elimination reactions, substitution reactions, pericyclic reactions, rearrangement reactions, mechanistic organ ...
and a variation of the
Diels–Alder reaction
In organic chemistry, the Diels–Alder reaction is a chemical reaction between a Conjugated system, conjugated diene and a substituted alkene, commonly termed the Diels–Alder reaction#The dienophile, dienophile, to form a substituted cyclohexe ...
in which a suitable
diene
In organic chemistry, a diene ( ); also diolefin, ) or alkadiene) is a covalent compound that contains two double bonds, usually among carbon atoms. They thus contain two alk''ene'' units, with the standard prefix ''di'' of systematic nome ...
reacts with an
aldehyde
In organic chemistry, an aldehyde () (lat. ''al''cohol ''dehyd''rogenatum, dehydrogenated alcohol) is an organic compound containing a functional group with the structure . The functional group itself (without the "R" side chain) can be referred ...
to form a
dihydropyran In organic chemistry, dihydropyran refers to two heterocyclic compounds 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 ...
ring. This reaction is of some importance to synthetic organic chemistry.
:
The oxo-DA reaction was first reported in 1949 using a 2-methylpenta-1,3-diene and
formaldehyde
Formaldehyde ( , ) (systematic name methanal) is an organic compound with the chemical formula and structure , more precisely . The compound is a pungent, colourless gas that polymerises spontaneously into paraformaldehyde. It is stored as ...
as reactants.
:
Asymmetric oxo-DA reactions (including catalytic reactions) are well known.
[''Tetrahedron Report number 869 Asymmetric hetero-Diels–Alder reactions of carbonyl compounds'' Helene Pellissier ]Tetrahedron
In geometry, a tetrahedron (: tetrahedra or tetrahedrons), also known as a triangular pyramid, is a polyhedron composed of four triangular Face (geometry), faces, six straight Edge (geometry), edges, and four vertex (geometry), vertices. The tet ...
65 (2009) 2839–2877 Many strategies rely on coordinating a
chiral Lewis acid to the carbonyl group.
See also
*
Aza-Diels–Alder reaction
References
{{DEFAULTSORT:Oxo-Diels-Alder reaction
Cycloadditions
Oxygen heterocycle forming reactions
Name reactions