An Oxo Diels–Alder reaction is an organic reaction and a variation of the Diels-Alder reaction in which a suitable diene reacts with an aldehyde to form a dihydropyran ring. This reaction is of some importance to synthetic organic chemistry.
The oxo DA reaction was first reported in 1949 [1] using a methylpentadiene and formaldehyde as reactants.
Asymmetric oxo-DA reactions (including catalytic reactions) are well known.[2] Many strategies rely on coordinating a chiral Lewis acid to the carbonyl group.