One Pot Diastereoselective Synthesis of New Chiral Spiro-1,3,4-thiadiazoles and 1,4,2-Oxathiazoles from (1R)-Thiocamphor.
One Pot Diastereoselective Synthesis of New Chiral Spiro-1,3,4-thiadiazoles and 1,4,2-Oxathiazoles from (1R)-Thiocamphor.
复制标题
从 (1R)-硫樟脑一锅法非对映选择性合成新型手性螺-1,3,4-噻二唑和 1,4,2-氧噻唑。
DOI：
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发表时间：
2004
期刊：
影响因子：
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通讯作者：
J. Daran
中科院分区：
文献类型：
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作者：
Amal Feddouli;M. Y. A. Itto;A. Hasnaoui;D. Villemin;P. Jaffrès;Jana Sopkova;A. Riahi;François Huet;J. Daran
在此，我们报道了新型手性4,5-二氢-4-芳基螺[1,3,4-噻二唑]-5,2'-莰烷-2-甲酸乙酯5-7和4,5-二氢-3-芳基螺[1,4,2-恶噻唑]-5,2'-莰烷11-13的高效一锅法合成，使用方法 腈亚胺 2-4 和腈氧化物 8-10 分别与 (1R)-硫樟脑 1 进行 1,3-偶极环加成。新制备的1,3,4-噻二唑5-7（以纯非对映异构体形式获得）的结构通过光谱分析和X射线结构分析完全确定，证明C5螺环碳的绝对构型为(R)。 NMR 光谱分析也非常有用，表明新的 1,4,2-恶噻唑 11-13 是两种 (5R)/(5S) 非对映异构体的混合物，其比例分别为 6:4,7:3 和 6:4。
Herein we report an efficient one pot synthesis of new chiral 4,5-dihydro-4-arylspiro[1,3,4-thiadiazole]-5,2′-camphane-2-carboxylic acid ethyl esters 5–7 and 4,5-dihydro-3-arylspiro[1,4,2-oxathiazole]-5,2′-camphane 11–13, using 1,3-dipolar cycloaddition of nitrilimines 2–4 and nitrile oxides 8–10 to (1R)-thiocamphor 1 respectively. The structure of the newly prepared 1,3,4-thiadiazoles 5–7 (obtained as pure diastereoisomers) were fully established via spectroscopic analysis and X-ray structural analysis which proved the absolute configuration of the C5 spiranic carbon to be (R). NMR spectral analysis were also very useful to show the new 1,4,2-oxathiazoles 11–13 are mixtures of two (5R)/(5S) diastereoisomers with the ratio 6:4,7:3 and 6:4 respectively.