Synthesis of substituted 1,4-oxathianes. Mechanistic details of diethoxytriphenylphosphorane and triphenylphosphine/tetrachloromethane-promoted cyclodehydrations and carbon-13 NMR spectroscopy
Synthesis of substituted 1,4-oxathianes. Mechanistic details of diethoxytriphenylphosphorane and triphenylphosphine/tetrachloromethane-promoted cyclodehydrations and carbon-13 NMR spectroscopy
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取代的1,4-氧杂环己烷的合成。
DOI：
10.1021/jo00380a009
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发表时间：
1987
影响因子：
3.6
通讯作者：
S. Evans
中科院分区：
文献类型：
--
作者：
W. T. Murray;J. Kelly;S. Evans
二乙氧基三苯基正膦（DTPP）引发2，2 '-双（羟乙基）硫醚的立体定向环化脱水，通过GLC和~（13）C NMR分析，一步（70-85%）生成相应的1，4-氧硫杂环己烷。Ph 3 P/CCl 4-和Ph 3 P（OEt）2-促进的环化脱水的机理细节通过特定的氘标记结合和13 C NMR光谱来探测。取代的1，4-氧硫杂环己烷是合成具有生物活性的1，4-氧硫杂环英的重要前体，而1，4-氧硫杂环英本身又是杀菌剂和杀虫剂。1此外，取代的1，4-氧硫杂环己烷及其S-氧化物的立体化学和构象描述也引起了相当大的关注。[2]虽然有几种制备方法可用于它们的构建，但很少显示出适合于在碱性杂环内战略性放置各种取代基的合成通用性。3我们实验室最近的研究结果表明，二乙氧基三苯基正膦（DTPP）可用于将二醇转化为环醚，将4，-巯基醇转化为环硫化物，将5和β-氨基醇转化为氮杂环丙烷。6因此，我们设想DTPP将有效地将取代的2，2 '-双（羟乙基）硫醚转化为1，4-氧硫杂环已烷。这似乎是合理的，这一目标也可以实现高区域和立体特异性，因为与DTPP环化脱水的二醇的机制不涉及步骤，将com-bind-
Diethoxytriphenylphosphorane (DTPP) initiates stereospecific cyclodehydrations of 2, 2'-bis (hydroxyethyl) sulfides to the corresponding 1, 4-oxathianes in a single step (70-85%) by GLC and 13C NMR analyses. The mechanistic details of Ph3P/CCl4-and Ph3P (OEt) 2-promoted cyclodehydrations are probed by specific deuterium labeling in combination with and 13C NMR spectroscopy. Carbon-13 NMR shift correlations, which are valuable for stereochemical and conformational assignments of substituted 1, 4-oxathianes, are also reported.Substituted 1, 4-oxathianes are important precursors in the synthesis of biologically significant 1, 4-oxathiins, which are themselves useful as fungicides and pesticides. 1 In addition, stereochemical and conformational descriptions of substituted 1, 4-oxathianes and their S-oxides have at-tracted considerable attention. 2 While several preparative methods are available for their construction, few exhibit the synthetic versatility suitable for strategic placement of various substituents within the basic heterocycle. 3 Results of recent studies from our laboratories have demonstrated that diethoxytriphenylphosphorane (DTPP) is useful for converting diols to cyclic ethers, 4,-mercapto alcohols to cyclic sulfides, 5 and ß-amino alcohols to aziridines. 6 Therefore, we envisioned that DTPP would ef-ficiently convert substituted 2, 2'-bis (hydroxyethyl) sulfides to 1, 4-oxathianes. It seemed reasonable that this objective could also be accomplished with high regio-and stereo-specificity since the mechanism of cyclodehydration of diols with DTPP does not involve steps that would com-