Syntheses of Quinolino-fused Bicyclo [2.2.2] octadienes and Sesquibicyclo [2.2.2] octadienes from Friedländer Reaction

• Main Authors: Shang-Ta Chao, 趙尚達
• Other Authors: Cheng-Tung Lin
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/78220567942955274303

碩士 === 東海大學 === 化學系 === 96 === The Synthesis of quinolino-fused bicycle[2.2.2]octadiene 63, sesquibicyclo[2.2.2]octadienes 71, 72, 80, 81 and the corresponding quinoline derivatives 64, 73, 82, 83 has been achieved. The UV spectra of these quinoline derivatives reveal a slight transannular interaction between quinoline moiety and bridged carbon-carbon double bonds. Reduction of o-nitrobenzaldehyde gave o-aminobenzaldehyde (62). Friedländer condensation of the resultant 62 with 61, 55, 56 produced quinoline derivative 63, 71, 72 respectively. Catalytic hydrogenation of 63, 72 gave quinoline analogs 64, 73. Diels-Alder reaction of 1,3-cyclohexadiene moiety resulting from decarbonylation of 74 with α-chloroacrylyl chloride (75), followed by subsequent Curtius rerreagement and acidic hydrolysis produced the mixture of tetracyclic adducts 76a, 76b. Ester exchange reaction of 76a, 76b afforded isomeric 77. Oxidation of hydroxyl group of 77 by PCC gave an inseparated isomers 78. Friedländer condensation of 62 with 78 produced quinoline derivatives 80, 81. Catalytic hydrogenation of 80, 81 gave the corresponding quinoline analogs 82, 83. In comparison with the analogs 64, 73, 82, 83, the UV spectra of quinoline derivatives 63, 71, 72, 80 and 81 show a bathochromic shifts of 1~3 nm of the large wavelength absorption band and a significant increase in extinction coefficients. This result may be attributed to orbital interaction between quinoline ring and etheno bridges. Transannular interaction between non-conjugated carbonyl -electrons in rigid sesquibicyclo[2.2.2]octadiene has been demonstrated by comparing the 13C-NMR shift values of the sp2 carbons. The chemical shift increased (down field shift) by 5 ppm when parallel etheno bridges are hydrogenated implies the strong interaction between two separated C=O chromophores.