作者:Satoshi Sakaguchi、Daisuke Kikuchi、Yasutaka Ishii
DOI:10.1246/bcsj.70.2561
日期:1997.10
NaBrO3 combined with NaHSO3 was found to be an excellent oxidizing reagent of alcohols, diols, and ethers under mild conditions. A variety of aliphatic and cyclic diols were selectively oxidized with satisfactory yields to the corresponding hydroxy ketones and/or diketones, which are difficult to selectively prepare due to a concomitant formation of cleaved products. For example, 2-hydroxycyclohexanone and 1,2-cyclohexanedione were selectively formed by allowing 1,2-cyclohexanediol to react with NaBrO3/NaHSO3 reagent in a selected solvent. On the other hand, an alkyl ether, such as dioctyl ether, reacted with NaBrO3/NaHSO3 in water at room temperature to give octyl octanoate in 82% yield. The same oxidation at higher temperature (60 °C) produced the α-brominated ester, octyl 2-bromooctanoate, which is considered to be formed through an alkenyl alkyl ether as the intermediate. The treatment of 1-ethoxy-1-heptene with NaBrO3/NaHSO3 afforded ethyl 2-bromoheptanoate and 2-bromoheptanoic acid as the major products.
NaBrO3与NaHSO3组合被发现是一种在温和条件下对醇、二醇和醚类具有优异氧化能力的试剂。多种脂肪族和环状二醇被选择性地氧化为相应的羟基酮和/或二酮,产率令人满意,这些产物由于伴随生成断裂产物而难以选择性制备。例如,通过在选定溶剂中使1,2-环己二醇与NaBrO3/NaHSO3试剂反应,选择性地生成了2-羟基环己酮和1,2-环己二酮。另一方面,在室温下,二辛醚在水中的NaBrO3/NaHSO3反应以82%的产率得到了辛基辛酸酯。同样的氧化反应在较高温度(60°C)下产生了α-溴代酯,即辛基2-溴辛酸酯,这被认为是通过烯基烷基醚作为中间体形成的。使用NaBrO3/NaHSO3处理1-乙氧基-1-庚烯,主要产物是乙基2-溴庚酸酯和2-溴庚酸。