Synthesis and 1H and 13C NMR structural analysis of cis- and trans-2-imino-1,3- and -3,1-perhydrobenzoxazines and their 3- and 1-N-methyl derivatives

Kalevi Pihlaja, Jari Sinkkonen, Ferenc Fülöp

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

cis- and trans-2-imino-1,3- and -3,1-perhydrobenzoxazines and the N-methyl derivatives of the latter were synthesized from the corresponding cyclic 1,3-amino alcohol with cyanogen bromide. The configurations of the studied compounds were confirmed by 1H and 13C NMR spectra. All trans-fused compounds exist in biased chair-chair conformations as expected, whereas the cis-fused 1,3-benzoxazines attain exclusively the O-in conformations. The cis-fused 3,1-benzoxazines, especially the 1-methyl-substituted derivatives, tend to favor the N-out form, obviously owing to the favorable axial orientation of this N-methyl.

Original languageEnglish
Pages (from-to)435-440
Number of pages6
JournalMagnetic Resonance in Chemistry
Volume41
Issue number6
DOIs
Publication statusPublished - Jun 1 2003

Keywords

  • Benzoxazines
  • C NMR
  • Conformational analysis
  • H NMR
  • Heterocycles
  • NMR

ASJC Scopus subject areas

  • Chemistry(all)
  • Materials Science(all)

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