80322-72-1

Upstream product

• 67-56-1 methanol 
• 124462-47-1 5,6-dihydro-3-phenyl-6-(trimethylsiloxy)-4H-1,2-oxazine 
• 80322-70-9 6-ethoxy-5,6-dihydro-3-phenyl-4H-1,2-oxazine 
• 21572-32-7 2-chloro-1-phenyl-ethanone oxime 

Downstream Products

• 105623-50-5 2,3-dibenzoyl-6-methoxy-3a-phenyl-3a,4,5,6-tetrahydropyrrolo<1,2-b>isoxazole 

Relevant academic research and scientific papers

Transition Metal- and Acid-Induced Transformations of 6-Siloxy-Substituted 5,6-Dihydro-4H-1,2-oxazines: Preparation of Pyrroles, Nitrones, 1,4-Dicarbonyl Compounds and Derivatives Thereof

A variety of 6-siloxy-substituted 5,6-dihydro-4H-1,2-oxazines (abbreviation: 1,2-oxazines) 1, 3 could be transformed into di- and trisubstituted pyrroles 2, 4 by means of molybdenum hexacarbonyl.The mechanism of this deoxygenating ring contraction is discussed.With two bicyclic 1,2-oxazines an acid-catalyzed fragmentation affording α-methylenecycloalkanones 7 has been observed, while other 1,2-oxazines rearrange in methanolic acid to give nitrones 9, 10.The desilylation of 6-siloxy-substituted 1,2-oxazines 1.3 employing NEt3*3HF is a very general and smooth process providing 6-hydroxy-1,2-oxazines 11, 12 or their corresponding acyclic tautomers 13, 14 in high yields.For two examples of 11 deoximations by use of formalin could be achieved with moderate efficiency giving 1,4-dicarbonyl compounds 15.

Acid-catalysed Rearrangement of 3-Acyl-6-alkoxy-5,6-dihydro-4H-1,2-oxazines: a Route to 3-Alkoxypyridine 1-Oxides

6-Alkoxy-5,6-dihydro-4H-1,2-oxazines (2) and (5) have been prepared by the reaction of chloro oximes (1) with enol ethers in the presence of sodium carbonate.The 3-phenyloxazine (2) rearranges to the nitrone (3) in methanolic HCl.In contrast, the 3-acyloxazines (5a-e) are converted into 3-alkoxypyridine 1-oxides (7) in aqueous alcoholic HCl.With HCl in acetic acid the oxazine (5a) is converted into 2-chloromethyl-3-hydroxypuridine hydrochloride (10a); analogous reactions take place with oxazines (5b) and (5d).Possible mechanisms for these reactions are discussed.

A New Route to 3-Alkoxypyridine 1-Oxides

Dihydro-oxazines, prepared by the addition of enol ethers to 1-chlorobutane-2,3-dione 2-oxime, are converted into 3-alkoxypyridine 1-oxides by the action of alcoholic HCl.