Efficient synthesis of tricyclic benzobisoxazines by silica gel catalysis.
A new method for the synthesis of tricyclic benzobisoxazines, based upon silica gel-catalyzed formation of two 3,1-oxazine rings, is reported. The reversibility of the condensation reaction, forming an oxazine ring, allows for implementation of silica gel catalyzed ketone exchange in benzobisoxazine, thus enabling access to nonsymmetric derivatives of benzobisoxazines.
Spagnol
Gaëlle
G
Department of Chemistry, University of Nebraska, Lincoln, NE 68588-0304, USA.
Rajca
Andrzej
A
Rajca
Suchada
S
D000447:Aldehydes / Q000737:chemistry; D048588:Benzoxazines / Q000138:chemical synthesis*; D002384:Catalysis; D002855:Chromatography, Thin Layer; D007659:Ketones / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D058428:Silica Gel; D012822:Silicon Dioxide / Q000737:chemistry*
D000447:Aldehydes; D048588:Benzoxazines; D007659:Ketones; D058428:Silica Gel; D012822:Silicon Dioxide