Thermal Addition Reaction of Aroylketenes with Cyclic Enol Ethers

抄録

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