X-Ray study of hetero ring flexibility in norbornane, norbornene-fused 1,3-oxazin-2-thiones Structure of 5,8-methano-r-4-phenyl-c-4a, c-5,6,7,c-8,c- 8a-hexahydro-4H- 1,3-benzoxazin-2 (3H)-thione

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The structure of S,8-methano-r-4-phenylc4a,c5,6,7c8c8ahexahydro4H 1,3 -benzoxazin- 2 (3H)-thione (C15H17N0S, Mr=259.37) has been established by X-ray crystallography from diffractometer data: it crystallizes in the monoclinic space group P21/n with a=6.150(2) Å, b=9.655(1) Å, c=22.093(4) Å,β=96.75(2)† V=1302.7(8) Å3,4,Dc=1.32gcm-3and p(Cu K) =20.4cm-. The structure has been solved by direct methods, refined to R=0.050 for 2193 observed reflections. The X-ray analysis substantiated the structure: the NMR spectra in- dicated that the 4-phenyl group assumes an exo-equatorial position. The puckering parameters of D. Cremer, J.A. Pople, J. Am. Chem. Soc., 97 (1975), 1354 (ref.1), of the distorted hetero ring (a transitional form between E4-envelope, (5S4-screw-boat) show that, depending on the positions of the hetero atoms, both the norbornane, norbornene skeletons markedly alter the characteristic transitional (5E/5H6) shape of the 1,3-oxazine ring observed in other saturated, partly saturated l,3-benzoxazin-2-ones, analogous thiones.

Original languageEnglish
Pages (from-to)167-177
Number of pages11
JournalJournal of Molecular Structure
Issue number1-2
Publication statusPublished - Aug 1 1991


ASJC Scopus subject areas

  • Analytical Chemistry
  • Spectroscopy
  • Organic Chemistry
  • Inorganic Chemistry

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