Preparation and ESR-Spectroscopical Investigation of Remarkably Persistent Oxoisobenzofuranyl Radicals

Article abstract of DOI:10.1002/hlca.19930760503

The synthesis of the diastereomeric 1,1'-diaryl-1,1'-bi(isobenzofuran)-3,3'(1H,1'H)-diones 3a-d starting from the readily available 2-aroylbenzoic acids 1a-d is described (Scheme 1).Of the colourless dimers 3a-d, only the sterically congested 3a and 3b di