The Study of Radical Addition to the Carbonyl compounds

• Main Authors: Chang, Sheng-Yueh, 張聖岳
• Other Authors: Tsai, Yeun-Min
• Format: Others
• Language: zh-TW
• Published: 1996
• Online Access: http://ndltd.ncl.edu.tw/handle/81405885223636904419

博士 === 國立臺灣大學 === 化學學系 === 84 === In thisreasearch, We studied the radical addition to carbonyl compounds. It was divided into four parts. In the first part, the intramolecular free radical addition to acylsilane followed by radical Brook rearrangement was discussed. In order to find the scope and limitations of this type of reactions, we have al- so ivestigated the steric effects of silyl groups, the influence of different carbon chain length connecting the radical and acy- lsilane, and the use of different types of radicals. In the second part, the focus was to expand the utility of the radical reactions mentioned above. The omega- bromo-omega-tribu- tylstannyl acylsilanes or omega-xanthate- omega-tributylstannyl acylsilanes were treated with catalytic amount of tributyltin hydride. Regiospecific enol silyl ethers were obtained in good yields. This process involoves the generation of a terminal alpha-stannyl radical followed by 1,5-exo-cyclization and radic- al Brook rearrangement to give a carboradical. A facile beta- scission then occurs to obtain an enol silyl ether, and regener- ated tributyltin radical to continue radical reactions.