Oxazine derivativesOxazine derivatives R 0595 Molecular and Crystal Structure of 2,3,4,5,6,7,8-Heptachloro-2-morpholinocarbonyltricyclo[4.3.0.0 1,3 ]nona-4,7-dien-9-one. -Morpholine (II) is added to the tetrachlorocyclopentadienone dimer (I) forming a new tricyclic compound (III). -(GIMALOVA, F. A.; GAVRILOV, O. A.; LUBETSKY, D. V.; MIFTAKHOV*, M. S.; Russ.