Attempted cyclization of (4-(hydroxymethyl)-8-nitro-4H-benzo[b]tetrazolo[1,5-d][1,4]oxazin-4-yl)methyl 4-methylbenzenesulfonate 2 did not give the expected spirooxetane product 1, but instead provided 9-nitro-5H-spiro[benzo[b]tetrazolo[1,5-d][1,4]oxazepine-4,2′-oxirane] 3 via an unusual ring-expansion process. The structure of compound 3 was confirmed by single-crystal X-ray crystallography. The spiroepoxide (oxirane) in compound 3 could be ring-opened with a variety of nucleophiles to give products of potential interest to medicinal chemists.

中文翻译：

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通过不寻常的扩环合成9-硝基-5 H-螺[苯并[ b ]四唑并[1,5- d ] [1,4]氧杂氮杂-4,2'-环氧乙烷]

的尝试环化（4-（羟甲基）-8-硝基-4- ħ -苯并[ b ]四唑并[1,5- d ] [1,4]恶嗪-4-基）甲基4-甲基苯磺酸酯2没有给出预期螺氧杂环丁烷产物1，但通过不寻常的扩环过程提供了9-硝基-5 H-螺[苯并[ b ]四唑[1,5- d ] [1,4]奥氮平-4,2'-环氧乙烷] 3 。化合物3的结构通过单晶X射线晶体学确认。化合物3中的螺环氧化物（环氧乙烷）可以用各种亲核试剂进行开环，以使药物化学家可能感兴趣的产品。