The structure of the pentacyclic title compound, C23H23NO3, was established by X-ray diffraction. The exo positions of the aryl group, indicated by the NMR data, were confirmed by the relevant torsion angles: C11-O10-C2-C19 = -79.7(3), C4-N3-C2-C19 = -98.5(3) and C13-N3-C2-C19 = 86.2(4)degrees. The position of the aryl group is stabilized by a C24-H24...N3 interaction [H24...N3 2.480(2), C24...N3 2.855(4)Angstrom, C24-H24...N3 98.7(2)degrees]. The conformations of the benzoxazine rings I and II are twist-boat (T-1(3)) and screw-boat (S-1(6)), respectively.
Stajer, Geza; Frimpong-Manso, Samuel; Bernath, Gabor, Journal of Heterocyclic Chemistry, 1991, vol. 28, # 3, p. 753 - 757
作者:Stajer, Geza、Frimpong-Manso, Samuel、Bernath, Gabor、Sohar, Pal