Hexahydro- 3a,c and tetrahydroisoindolo[2,1-α][3,1]-benzoxazine-6,12- diones 3b,d were prepared by the reaction of 2-carboxybenzaldehyde (1) with diendo- and diexo-3-aminobicyclo-[2.2.1]hexane/ene-2-carboxylic acids 2a-d. When heated, 3b and 3d (containing a norbornene structural moiety) undergo retrodiene decomposition by splitting off cyclopentadiene to give the 1,3- oxazino[2,3-α]isoindole-2,6-dione (4). This is the first example of the preparation of a condensed heterotricyclic compound in a retro Diels-Alder reaction. The results reveal that this reaction can be extended to the formation of new condensed-skeleton polycyclic hetero compounds which have an electron-rich moiety in the terminal ring of the fused heterocycle formed by the splitting off of cyclopentadiene. The structures of the pentacyclic hetero compounds 3a-d were determined by NMR spectroscopy.
|Number of pages||3|
|Publication status||Published - May 1 1998|
- 1,4- Methanohexahydro- and tetrahydroisoindolo[2,1-α]-[3,1]-benzoxazine-6,12- diones
- Retro Diels-Alder
ASJC Scopus subject areas
- Organic Chemistry