Preparation and NMR determination of structures of tri‐, tetra‐ and pentacyclic isoindolone derivatives

Abstract From the reactions of 3‐endo‐benzoyl‐6‐exo‐phenylbicyclo[2.2.1] heptane‐2‐endo‐carboxylic acid (2) and α,ω‐diamines or o‐aminophenol/thiophenol, different tri‐, tetra‐ and pentacyclic phenyl‐substituted norbornane‐condensed heterocycles were prepared. With ethylenediamine, 2 furnished two isomeric imidazolo[2,1‐a]isoindolones. In the formation of one of them, an end→oexo isomerizaton was observed. The stereostructures (configurations and conformations) of the compounds were elucidated by 1H and 13C NMR spectroscopy, with the aid of routine spectra and also DR, DNOE, DEPT, COLOC and 2D‐HSC measurements.