1,3-Dipolar Cycloaddition of 5-Methoxy-1-methy1-3-oxidopyridinium Synthesis of Phenyl Tropone

• Main Author: 林孟嬌
• Other Authors: 陳麟慶
• Format: Others
• Language: zh-TW
• Published: 1994
• Online Access: http://ndltd.ncl.edu.tw/handle/50274909882126174641

碩士 === 高雄醫學大學 === 藥學研究所 === 82 === 1,3-Dipolar cycloaddition of l-methyl-3-oxidopyridinium (8) has been the subject of much synthetical interest. However, the application is quite limited because of insufficient 1,3-dipolar reactivity of the betaine (8), the reaction succeeds with olefinic dipolarophiles containing a strongly electron-withdrawing group, but fails with other olefins. In order to increase the reactivity of the betaine several attempts has been made, and replacement of the methyl group on the nitrogen of (8) by electronwithdrawing substituent as in the betaine (10) was reported to be effective. The synthesis of phenyl tropone based on the 1,3-dipolar reactivity of 5-methoxy-l-methyl-3-oxidopyridinium (1) is described.