Abnormal Beckmann Rearrangement of Spiroketoximes in Polyphosphoric Acid
Abnormal Beckmann Rearrangement of Spiroketoximes in Polyphosphoric Acid
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多磷酸中螺酮肟的异常贝克曼重排
DOI：
10.1021/ja01488a037
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发表时间：
1960
影响因子：
15
通讯作者：
R. Conley
中科院分区：
文献类型：
--
作者：
R. K. Hill;R. Conley
具有肟碳α螺原子的螺酮肟的贝克曼重排已在各种条件下进行。使用亚硫酰氯或五氯化磷，大多数产生正常内酰胺产物和“二级”裂解产物（不饱和腈）的混合物。螺环戊酮肟在多磷酸中的重排导致高产率地生成双环1/3-不饱和酮，这被证明是由不饱和腈的酸催化环化产生的。在这些条件下，螺环己酮肟还产生β-不饱和酮、少量内酰胺和大量饱和酰胺。螺-[环戊烷-1, 2'-假吲哚氧基]肟被多磷酸裂解为环戊酮和邻氨基苯甲酰胺。在贝克曼重排条件下发生“异常”反应的酮肟类中，碳原子完全被取代；这些肟经常裂解为不饱和腈或 烯烃和腈的混合物 3 该反应的一个显着特征是其进程取决于所使用的特定试剂。例如，α-苯基异丁酰苯肟在乙酸中与氯化氢重排为二甲基苯乙酰苯胺，但被亚硫酰氯裂解为苯甲腈和甲基苯乙烯。 2j 皮瓦洛-
The Beckmann rearrangement of spiroketoximes having the spiro atom alpha to the oxime carbon has been carried out under various conditions. Using thionyl chloride or phosphorus pentachloride, most yielded mixtures of the normal lactam product and the product of a “second-order" cleavage, an unsaturated nitrile. The rearrangement of spirocyclopentanone oximes in polyphosphoric acid led in highyield to bicyclic,/3-unsaturated ketones, which were shown to result from acid-catalyzed cyclization of the unsaturated nitriles. Under these conditions, spirocyclohexanone oximes yielded, besides, ß-unsaturated ketones, small amounts of lactams and larger quantities of saturated amides. Spiro-[cyclopentane-1, 2'-pseudo-indoxyl] oxime was cleaved by polyphosphoric acid to cyclopentanone and anthranilamide.Among the classes of ketoximes which undergo “abnormal’’reactions when subjected to Beckmann rearrangement conditions are those completely substituted at an-carbon atom; these oximes often cleave to unsaturated nitriles or to mixtures of olefin and nitrile 3 A striking featureof the reaction is the dependence of its course upon the particular reagent employed. a-Phenylisobutyro-phenone oxime, for example, rearranges to di-methyl phenylacetanilide with hydrogen chloride in acetic acid, but is cleaved by thionyl chloride to benzonitrile and-methylstyrene. 2j Pivalo-