[4+2] Cycloaddition Reactions of 4-Thio-Substituted-2-Pyridones

• Main Author: 王慧貞
• Other Authors: Shang-Shing P. Chou
• Format: Others
• Language: zh-TW
• Published: 2003
• Online Access: http://ndltd.ncl.edu.tw/handle/27972077383384254923

碩士 === 輔仁大學 === 化學系 === 91 === Abstract This thesis mainly studies the [4+2] cycloaddition reactions of 4-thio-substituted-2-pyridones undergo , and discuss the effect of the thio group and N-substituents on the yield and regio- , stereo selectivity of the reaction. In the cycloaddition, if we choose suitable dienophiles such as maleimide derivatives to react with pyridones 6a and 6b , we can avoid the N→O migration side reaction, and can obtain the expect cycloaddition products. These results show that the tosyl group on the nitrogen plays an important role on the stereo selectivity, and different C4-thio groups also influence the yield because of the electronic effect. The N-tosyl group of the 4-thio-substituted-2-pyridones 6a, 6b can be converted into N-alkyl substituent by the radical approach followed by alkylation. The cycloaddition reactions of these compounds 15-16 with N- phenylmaleimide have also been studied.