Synthesis Of γ-lactam Derivatives Via Intramolecular Ene Reaction And Aryl Involved Intramolecular Diels-Alder Reaction

Intramolecular ene reaction and intramolecular Diels-Alder cycloaddition are two kinds of important reactions for efficiently forming carbon-carbon bonds in organic synthesis, they are effective means to build ring structures. The topic of this thesis is the synthesis of y-lactam derivatives via intramolecular ene reaction and aryl involved intramolecular Diels-Alder reactions.In the first chapter of this thesis, the mechanism of ene reaction and Diels-Alder reaction were described briefly. The affecting factors of the phenyl involved intramolecular Diels-Alder reaction as well as the impact of activating group and the stereoselectivity of the intramolecular ene reaction were discussed also. Besides, there was a brief introduction to the phenyl involved intramolecular Diels-Alder reactions and intramolecular ene reactions in organic synthesis applications.In the second chapter of this thesis the research purpose that synthesis of substrates with different structures to study the inrtramolecular ene reaction and phenyl involved intramolecular Diels-Alder reaction of them and to synthesize highly substituted y-lactam derivatives which contain complex structures at the same time was described. Based on this research purpose, a variety of amide tethered1,6-diene substrates were synthesized through a reasonably designed synthetic route. In acetonitrile, heated in sealed vial, amide tethered1-methyl-or7-methyl-1,6-diene substrates (2.37a-d,2.40b-c) occured the intramolecular ene reaction, amide tethered1,7-dimethyl-1,6-diene substrate (2.40a) reacted regioselectively to afford intramolecular ene reaction products, affected by the activated group at7-carbon; however, amide tethered1-phenyl-7-methyl-1,6-diene substrates, when the benzene ring with weak electron-withdrawing or electron donating groups (2.37e-h), ene reaction occured only, but when connected a strong electron-withdrawing group, nitro group (2.44), the main product was afforded via benzene ring involved intramolecular Diels-Alder reaction.N-Allyl-2-coumarin carboxamides (2.52) occured benzene ring involved intramolecular Diels-Alder reaction followed retro-Diels-Alder reaction of carbon dioxide removal, when having ester group at3-position of allyl (2.52a-d), a single product was obtained; or when having only methyl group at3-position of allyl (2.52e-g), the yield of the reaction product were low, and there were some intramolecular ene products. Additionally, further modification of the above reaction products led to obtain of highly substituted y-lactams and y-lactams with four rings including one six-membered lactone ring. By X-ray diffraction analysis, four of the absolute configuration of the products was identified, and through1H NMR,13C NMR, IR, MS spectrometry analysis, the structure of other products were deduced. The experimental results were discussed through a possible reaction mechanism.The experimental section, the experimental procedures, the characterization data for the key intermediates and the final products, the cited references, the copies of original1H and13C NMR spectra and X-ray diffraction analysis data are listed at the end of the thesis.