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Compounds with bridgehead nitrogen 68—NMR spectra and stereochemistry of perhydropyrido [1,2-c] [1,3]oxazines

✍ Scribed by Trevor A. Crabb; Simon T. Ingate; Thomas G. Nevell

Publisher
John Wiley and Sons
Year
1992
Tongue
English
Weight
238 KB
Volume
30
Category
Article
ISSN
0749-1581

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✦ Synopsis

Abstract

Low‐temperature ^13^C NMR spectroscopy shows perhydropyrido [1,2‐c] [1,3]oxazine to adopt a conformational equilibrium in CD~2~Cl~2~–CFCl~3~ solution containing 98% trans fused conformer in equilibrium with 2% O‐outside‐cis fused conformer at 203 K. A similar equilibrium position is adopted by the trans‐(H‐4,H‐4a)‐4‐methylperhydropyrido[1,2‐c][1,3]oxazine, whereas the C‐4 epimer adopts exclusively the trans fused conformation.

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