Furazan N-oxides. Part 2. Synthesis and structure of some strained furazan N-oxides
Abstract
The strained furazan N-oxides (5) and (6) have been synthesised from norbornene and dicyclopentadiene by treatment with N2O3, thermal isomerisation of the resulting nitronitroso-adducts to the nitro-oximes [e.g.(9)], and subsequent dehydration at ambient temperature using SO3–DMF or CISO3H–DMF. Characterisation of the products is based on analytical and spectroscopic evidence by comparison with the known analogues (2) and (3), and in the case of (6) by X-ray crystal structure analysis. Compound (6) has endo-stereochemistry and is shown by 13C n.m.r. spectroscopy to be, like (2), a mixture of isomers, (6A) and (6B). X-Ray crystal structure analysis also showed that (3) has exo-stereochemistry and that for both (3) and (6) the O1–N2 bond of the oxadiazole is long (1.47 and 1.54 Å).
Please wait while we load your content...
