Modification of the Swern Oxidation: Use of Stoichiometric Amounts of an Easily Separable, Recyclable, and Odorless Sulfoxide That Can Be Polymer-Bound.
Modification of the Swern Oxidation: Use of Stoichiometric Amounts of an Easily Separable, Recyclable, and Odorless Sulfoxide That Can Be Polymer-Bound.
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DOI：
10.1021/jo961438d
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发表时间：
1996-11
期刊：
影响因子：
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通讯作者：
Yaoquan Liu;J. Vederas
中科院分区：
文献类型：
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作者：
Yaoquan Liu;J. Vederas
在使用草酰氯的Swern氧化反应中，使用容易获得的6-（甲基亚磺酰基）己酸（1）作为DMSO的替代物，以高产率顺利地将伯醇或仲醇转化为相应的醛或酮。得到的6-（甲硫基）己酸（2）可通过水萃取或通过硅胶过滤容易地分离，并可用偏高碘酸钠以97%的产率再氧化成1。低温（-60 ℃）（13）C NMR光谱法用于检查该Swern过程的中间体。结果表明，在烷氧基锍中间体的Pummerer消除过程中产生任何残留的未氧化的醇，并且可以通过在-40 ℃下延长暴露于三乙胺来最小化。1的钾盐与交联的氯甲基聚苯乙烯反应得到聚合物结合的试剂12，当以两倍过量使用时，该试剂12定量地将樟脑氧化成樟脑。
Readily available 6-(methylsulfinyl)hexanoic acid (1) is employed as a substitute for DMSO in Swern oxidation reactions using oxalyl chloride to smoothly convert primary or secondary alcohols to corresponding aldehydes or ketones in high yield. The resulting 6-(methylthio)hexanoic acid (2) is easily separable by aqueous extraction or by filtration through silica gel and can be reoxidized to 1 with sodium metaperiodate in 97% yield. Low temperature (-60 degrees C) (13)C NMR spectrometry is used to examine the intermediates of this Swern process. The results indicate that any residual unoxidized alcohol is generated during Pummerer elimination of the alkoxysulfonium intermediate and can be minimized by extended exposure to triethylamine at -40 degrees C. Reaction of the potassium salt of 1 with cross-linked chloromethyl polystyrene affords a polymer-bound reagent 12 that quantitatively oxidizes borneol to camphor when used in two-fold excess.