Synthesis,Structure, and Transformations of New Endic Anhydride Derivatives

4-Azatricyclo[5.2.1.02,6]dec-8-ene and its N-phenyl derivative were synthesized by reaction of endic anhydride with amines, transformation of the amido acids thus obtained to imides, and subsequent reduction of the latter with lithium aluminum hydride. The unsubstituted tricyclic amine was brought into reactions with electrophilic reagents: p-toluenesulfonyl chloride, p-toluoyl chloride, m-tolyl isocyanate, phenyl isothiocyanate, and endic anhydride to obtain a number of new derivatives; also, the corresponding salt with 1-adamantanecarboxylic acid was isolated. N-(p-Tolylsulfonyl)- and N-(m-tolylcarbamoyl)-4-azatricyclo-[5.2.1.02,6]dec-8-enes were oxidized to the corresponding 8,9-epoxy derivatives with monoperoxyphthalic acid. The structure of the products was confirmed by the data of IR, ¹H and ¹³C NMR, and mass spectra. The molecular structures of N-(p-iodophenyl)bicyclo[2.2.1]hept-2-ene-endo-5,endo-6-dicarboximide and N-phenyl-4-azatricyclo[5.2.1.02,6]dec-8-ene were established by X-ray analysis.     

Acylation of Aminopyridines and Related Compounds with Endic Anhydride

Reactions of bicyclo[2.2.1]hept-5-ene-endo-2,endo-3-dicarboxanhydride (endic anhydride) with 2-, 3-, and 4-aminopyridines, 3-hydroxy- and 5-iodo-2-aminopyridines, 6-aminoquinoline, and 6-aminoquinoxaline involve chemoselective transformation of the exocyclic amino group. The resulting amido acids were converted into the corresponding carboximides, and the latter were epoxidated with peroxy acids. The structure of the products was confirmed by the IR, UV, and ¹H and ¹³C NMR spectra, as well as by calculation of the ¹H and ¹³C chemical shifts using the GIAO method (B3LYP/6-31G** approximation).     

Reaction of Endic Anhydride with Hydrazines and Acylhydrazines

Reaction products of bicyclo[2.2.1]hept-2-ene-endo,endo-5,6-dicarboxylic (endic) acid with hydrazines and acylhydrazines were prepared. The features distinguishing of these reactions from those with amines were revealed. The compounds obtained were characterized by ¹H, ¹³C NMR, and IR spectra. The assignment of the signals in NMR spectra was done with the use of quantum-chemical calculations of chemical shifts performed by the density functional method. The structure of one among compounds synthesized, N-(m-hydroxybenzoylamino)-bicyclo[2.2.1]hept-2-ene-endo,endo-5,6-dicarboxamide, was proved by X-ray diffraction analysis.     

Products of endic anhydride reaction with cyclic amines and their heterocyclization

Products of reaction between bicyclo[2.2.1]hept-5-ene-endo-endo-2,3-dicarboxylic anhydride (endic anhydride) and cyclic amines were obtained. By an example of one of amido acids a conformational analysis was performed and character of hydrogen bonds was studied using quantum-chemical calculations by PM3 procedure. endo-3-(4-Antipyrylcarbomoyl)-bicyclo[2.2.1]hept-5-ene-endo-2-carboxylic acid with a secondary amide group was converted into the corresponding carboximide which was epoxidized by performic acid.     

Lactonization of epoxyendic anhydride in reactions with amines

Reactions of exo-5,6-epoxybicyclo[2.2.1]hept-5-ene-endo-2,endo-3-dicarboxylic anhydride (epoxyendic anhydride) with acyclic, aromatic, heteroaromatic, and nonaromatic heterocyclic amines afforded the corresponding heterocyclization products, substituted exo-2-hydroxy-5-oxo-4-oxatricyclo[4.2.1.0^3,7]nonane-endo-9-carboxamides (oxabrendanes), whose structure was confirmed by the IR and ¹H and ¹³C NMR (including two-dimensional) spectra. Other approaches to the tricyclic compounds were also examined, in particular via reactions of organic peroxy acids with amido acids obtained by aminolysis of endic anhydride.