The 11a,12-dihydrobenzo[b]benzo[5,6][1,4]oxazino[2,3-e][1,4]oxazine heterocyclic system has been used in the construction of heteropropellanes, which attracted much attention not only on the possible modification of drugs, but also for novel materials with unusual and important physical properties. In this communication, the reaction of ethyl 2-(hydroxyimino)propanoate 1 with disulfur dichloride and o-aminophenol, which gave ethyl 11a,12-dihydrobenzo[b]benzo[5,6][1,4]oxazino[2,3-e][1,4]oxazine-5a(6H)-carboxylate in moderate yield, was described. The structure of the newly synthesized compound was established by means of elemental analysis, high resolution mass-spectrometry, 1H, 13C NMR and IR spectroscopy, mass-spectrometry and X-ray analysis. [ABSTRACT FROM AUTHOR]