Hetero Diels-Alder reaction

Patent Pending Diels–Alder reactions involving at least one heteroatom are also known and are collectively called hetero-Diels–Alder reactions[39] Carbonyl groups, for example, can successfully react with dienes to yield pyranoid rings, a reaction known as the oxo-Diels–Alder reaction, and imines have also been successfully used as dienophiles; such reactions are known as aza-Diels–Alder reactions and prove useful for the preparation of alkaloids and other N-heterocyclic compounds.[40] Nitroso compounds (R-N=O) can react with dienes to form oxazines. Chlorosulfonyl isocyanate can be utilized as a dienophile to prepare the Vince lactam.