Investigation of the Diels-Alder cycloadditions of 2(H)-1,4-oxazin-2-ones.

The Journal of organic chemistry

PubMedID: 16268629

Afarinkia K, Bahar A, Bearpark MJ, Garcia-Ramos Y, Ruggiero A, Neuss J, Vyas M. Investigation of the Diels-Alder cycloadditions of 2(H)-1,4-oxazin-2-ones. J Org Chem. 2005;70(23):9529-37.
[Reaction: see text]. A variety of 5-chloro-2(H)-1,4-oxazin-2-ones bearing a range of substituents at their 3- and 6-positions undergo Diels-Alder cycloaddition as a 2-azadiene component with electron-rich, electron-deficient, and electron-neutral dienophiles. These reactions proceed with moderate regio- and stereoselectivity to afford relatively stable and readily isolable bridged bicyclic lactone cycloadducts. Chemical manipulation of these cycloadducts affords highly substituted and functionally rich piperidines. The regio- and stereochemical preferences of the cycloadditions of 5-chloro-2(H)-1,4-oxazin-2-ones are investigated computationally using density functional theory (B3LYP/6-31G).