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Stereostructure of cycloadducts of norbornane/ene‐fused dihydro‐1,3‐ and ‐3,1‐oxazines
Author(s) -
Sohár P.,
Stájer G.,
Bernáth G.
Publication year - 1987
Publication title -
magnetic resonance in chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.483
H-Index - 72
eISSN - 1097-458X
pISSN - 0749-1581
DOI - 10.1002/mrc.1260250715
Subject(s) - norbornane , chemistry , steric effects , benzonitrile , stereochemistry , oxazines , adduct , norbornene , dicyclopentadiene , yield (engineering) , ene reaction , organic chemistry , materials science , monomer , metallurgy , polymer , polymerization
The steric structures of the tetracyclic mono‐ and the pentacyclic bis‐adducts formed in the cycloadditions of norbornane‐ and norbornene‐fused 1,3‐ and 3,1‐dihydrooxazine dipolarophiles with diphenylnitrilimine or benzonitrile oxide were investigated. These reactions could yield 2–8 annellation and positional isomers. The structures of the products were proved by 1 H and 13 C NMR spectroseopy, and the various potentially stable conformations of the flexible hetero rings were evaluated. The assignments were confirmed by double resonance and DEPT measurements; the steric structures were supported by the results of DNOE experiments.