Mesoionische Sechsringheterocyclen, V [1, 2]; Reaktionen von 6-Oxo-6H-1.3-oxazin-3-ium-4-olaten mit o-Chinonen und Heterokumulenen / Mesoionic Six-Membered Heterocycles, V [1, 2] Reactions of 6-Oxo-6H-l,3-oxazin-3-ium-4-olates with o-Quinones and Heterocumulenes

Abstract

Abstract Mesoionic 6-oxo-6H-1,3-oxazine-3-ium-4-olates (1, 7) react with o-quinones (2, 4) to give compounds 3, 6, which may result from a primary [4+4]cycloaddition and subsequent loss of carbon dioxide. Phenyl isocyanate and phenylisothiocyanate react with 1h and 9 - possibly via a [2 + 4]cycloadduct - to give 11, 12, 13 and 14, respectively