Synthesis of 4-Ethoxycarbonyltropolones from Masked o-Benzoquinones

• Main Authors: Chuan-Yi Chang, 張逸專
• Other Authors: Chun-Chen Liao
• Format: Others
• Language: zh-TW
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/02484629516184641614

碩士 === 中原大學 === 化學研究所 === 99 === In this study, ethyl (dimethylsulfuranylidene) acetate (EDSA) was used for cyclopropanation reaction of MOBs to obtain bicyclo[4.1.0]heptenone systems, which were then converted to 4-ethoxycarbonyltropolones via acid-catalyted hydrolysis of the ketal group, ring expansion by boron trifluoride-ether and hydrolysis the difluoro borates. Furthermore, the structure of ring enlargement were revised. Difluoroborane is coordinating to both of the oxygen of the diketone forming a five-member ring. The removal of difluoroborane can be done by basic solution.