In the aza-variant of this reaction, an imine is substituted for one of the reactants, allowing for preparation of tetrahydropyridines.
In the aza-variant of this reaction, an imine is substituted for one of the reactants, allowing for preparation of tetrahydropyridines. Its desired end product and mechanism are similar the Prins Reaction, the Huisgen Reaction, and especially the Cope Rearrangement, which differs in that it uses a 1,5 starting product. Niobium pentachloride or another Lewis acid can often be used to catalyze it and sometimes to control the ratio of endo to exo product. The stereochemistry of substituents on the reactants is preserved in the product, as per the "cis principle" formulated by Stein and one of the reaction's namesakes. FTP, name this cycloaddition reaction that synthesizes a ring with a double bond from a conjugated diene and a dienophile, named for two German chemists.
In the aza-variant of this reaction, an imine is substituted for one of the reactants, allowing for preparation of tetrahydropyridines.
{Diels-Alder} reaction