Synthesis, oxidation and dehydrogenation of cyclic N,O- and N,S-acetals. Part III. Transformation of N,O-acetals: 3-acyl-1,3,4-oxadiazolines
作者:László Somogyi
DOI:10.1002/jhet.5570440603
日期:2007.11
Various aldehyde and ketone acylhydrazones are synthesized and, under acylating conditions, cyclized into 3-acyl-1,3,4-oxadiazolines. The scope and limitations of these cyclizations and the possible side reactions (e.g. formation of the open-chain N,O-acylhydrazinocarbinols) are dissected. For the first time, simple, convenient and efficient dehydrogenations of 3-acyl-1,3,4-oxadiazolines to oxadiazoles
合成了各种醛和酮酰基hydr,并在酰化条件下将其环化成3-酰基-1,3,4-恶二唑啉。剖析了这些环化作用的范围和局限性以及可能的副反应(例如,形成开链的N,O-酰基肼基碳氢化合物)。首次提出了通过高锰酸钾或更简单地用硝酸铈铈(IV)铵(CAN)处理将3-酰基-1,3,4-恶二唑啉简单,方便,有效地脱氢为恶二唑的方法。2,2-二取代的3-酰基-1,3,4-恶二唑啉以及醛二酰基hydr的CAN氧化(2,5-二取代的3-酰基-1,3,4-恶二唑啉的开链异构体)再生母体羰基化合物。