1,4-OxazineCCDC 956939. For crystallographic data in CIF or other electronic format see DOI: 10.1039/c3cc47801g

The fundamental heterocyclic compound 1,4-oxazine has been generated using FVP. It is the first parent heterocycle among all the possible isomeric oxazines, thiazines and their heavier atom analogues to be characterised spectroscopically, and is shown to exist in solution entirely as the 4 H -isomer. X-ray structure determination of the N -Boc precursor shows significant deviations from theoretically predicted geometric parameters. The fundamental heterocyclic compound 1,4-oxazine is generated and characterised spectroscopically for the first time.