Ketene. Part 25. Mechanistic studies of the reaction of nitrile oxides with ketenes
Ketene. Part 25. Mechanistic studies of the reaction of nitrile oxides with ketenes
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乙烯酮。
DOI：
10.1039/p19870000567
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发表时间：
1987
期刊：
影响因子：
--
通讯作者：
G. A. Taylor
中科院分区：
文献类型：
--
作者：
A. Evans;G. A. Taylor
17 O-标记的2，4，6-三甲基苄腈N-氧化物（4）与二甲基烯酮反应得到二氢恶唑酮加合物（5 b），同位素标记主要但不限于羰基。观察到标记的热扰乱，推测是通过两性离子（6）。提出二恶唑（8）作为（4）转化为（5 b）的中间体。（5 b）的碱性水解通过主要的氢氧化物攻击羰基得到（10 b）。尝试生成α-内酯（11）（通过碱金属α-卤代异丁酸酯的热分解）并将其加入苯甲腈和芴酮苯胺中，但没有成功。未检测到痕量化合物（5; Ar = Ph，R = Me）或（2; R1= Ph，R = Me），表明α-内酯不是二甲基烯酮与腈氧化物和硝酮形成加合物的中间体。
The reaction of 17O-labelled 2,4,6-trimethylbenzonitrile N-oxide (4) with dimethylketene gives the dihydro-oxazolone adduct (5b), with isotopic labelling predominantly, but not exclusively, in the carbonyl group. Thermal scrambling of the label is observed, presumably via the zwitterion (6). The dioxazole (8) is proposed as an intermediate in the conversion of (4) into (5b). Alkaline hydrolysis of (5b) gives (10b) by predominant hydroxide attack on the carbonyl group. Attempts to generate the α-lactone (11)(by thermal decomposition of alkali α-halogenoisobutyrates) and add it to benzonitrile and fluorenone anil were unsuccessful. No traces of compounds (5; Ar = Ph, R = Me) or (2; R1= Ph, R = Me) could be detected, suggesting that α-lactones are not intermediates in the formation of adducts of dimethylketene with nitrile oxides and nitrones.