AlCl3-catalysed addition of benzene to di-endo-bicyclo[2.2.1]hept-5-ene-2,3-dicarboxylic acid (1) and subsequent treatment with acetic anhydride yields 5-exo-phenylbicyclo[2.2.1]heptane-2,3-di-endo-carboxylic anhydride (2). 3-endo-Hydroxymethyl-5-exo-phenylbicyclo[2.2.1]heptane-2-endo-amine (4) was prepared by LAH reduction of the β-amino acid 3 obtained by Hofmann degradation of the carboxy amide prepared from 2. Reaction of 4 with ethyl chloroformate or with CS2-NaOH-Pb2+ furnished the methylene-bridged hexahydro-3,1-benzoxazin-2(1H)-one (5) or -benzoxazine-2(1H)-thione (6). With ethyl chloroacetate or 2-chloropropionate, 4 gave the tricyclic oxazepinones 7 and 8. The norbornane 1,3-amino alcohol 4 was transformed with phenyl isothiocyanate into the phenylimino-1,3-oxazine 9 and -thiazine 10. The cyclizations of 4 with 2-(p-methylbenzoyl)benzoic acid or cis-2-p-chlorobenzoyl-1-cyclohexanecarboxylic acid led to the methylene-bridged isoindolo[2,1-a][3,1]benzoxazines 11 and 12. With p-chlorobenzimidate, the di-endo-5,8-methano-4H-3,1-benzoxazine 13 was obtained, which was converted with dichloroacetic acid-triethylamine into the isomeric azetidinones 14 and 15, or with benzonitrile oxide to the methano-1,2,4-oxadiazolo[4,5-a][3,1]benzoxazine (16). The stereostructures of the new compounds were elucidated by NMR spectroscopy and for 13 also by X-ray diffractometry.
ASJC Scopus subject areas
- Chemical Engineering(all)