Thermal Addition Reaction of Aroylketenes with Cyclic Enol Ethers.
作者:Toshiaki SAITHOH、Taichi OYAMA、Yoshie HORIGUCHI、Jun TODA、Takehiro SANO
DOI:10.1248/cpb.44.1298
日期:——
Thermal reaction of aroylketenes 2 with cyclic enol ethers such as 2, 3-dihydrofuran (A), 2, 3-dihydropyran (B), 1-trimethylsilyloxycyclopentene (C), 1-trimethylsilyloxycyclohexene (D), 3-trimethylsilyloxyindene (E), and 4-trimethylsilyloxy-1, 2-dihydronaphalene (F) was carried out to investigate the reactivity of 2 with these olefins. The main reaction was Michael-type addition to give the 1, 3-diketones 3 and 9, and the 1, 3, 5-triketones 13, 15, 18, and 20, depending on the olefins used. The addition of the olefins was facilitated by introduction of a nitro or chloro group into the aryl part of 2 and was profoundly retarded by steric hindrance of the olefins
芳酰基
烯酮2与环状
烯醇醚如
2,3-二氢呋喃(A)、
2,3-二氢吡喃(B)、1-三
甲基硅氧基
环戊烯(C)、1-三
甲基硅氧基
环己烯(D)、3-三
甲基硅氧基
茚(E)和4-三
甲基硅氧基-
1,2-二氢萘(F)的热反应被进行,以研究2与这些
烯烃的反应性。主要反应是迈克尔型加成,产生1,3-二
酮3和9以及1,3,5-三
酮13、15、18和20,具体取决于所用的
烯烃。
烯烃的加入因2的芳基部分引入硝基或
氯原子而得到促进,并因
烯烃的空间位阻而显著减慢。