Compounds with Bridgehead Nitrogen Part 64 - Conformational Equilibria in the 6-p-Nitrophenylperhydrodipyridoimidazoles

Article abstract of DOI:10.1002/mrc.1260281208

The effect of 6-substitution on the conformational equilibria of the perhydrodipyrido<1,2-c:2',1'-e>imidazoles has been investigated. r-6H,t-11a,t-11b-6-p-Nitrophenylperhydrodipyrido<1,2-c:2',1'-e>imidazole was found to exist as a pair of enantiomeric non-interconverting N-outside-cis-syn-trans-conformers, whereas the r-6H,c-11a,c-11b and r-6H,c-11a,t-11b isomers adopted the trans-syn-trans conformations.Both syn isomers exhibit restricted rotation of the 6-p-nitrophenyl substituent at room temperature and below.