1.3- Oxazinium salts, 4-hydroxy-, reaction

Because of the highly electrophilic nature of the 1,2-oxazinium cation, virtually no studies have been carried out on isolated salts no general chemistry has been developed comparable to that of the pyrylium salts. There are, however, some reports of reactions in which 1,2-oxazinium salts are likely to be transient intermediates. Early work on 3,5,6-triaryl-l,2-oxazinium cations indicated that on hydration they are converted into the corresponding 6-hydroxy-6//-oxazinium cations (Equation... 

Methyl- and 3-phenyl-4-hydroxy-2-oxo-2//-pyrido[2,1 -Z)]oxazinium inner salts were prepared in the reaction of 2-pyridone and 2-substituted malonyl chloride, prepared in situ from 2-substituted malonic acid with PCI5 in CH2CI2 (00JCS(P2)2096). 

Methyl- and 3-phcnyl+-hydroxy-2-oxo-2//-pyrido[2,1 +]oxazinium inner salts were prepared in the reaction of... 

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