| 163579-70-2

• CAS: 163579-70-2；194495-12-0；163491-29-0
• 化学式: C₁₄H₁₄O₄W
• 分子量: 430.113
• InChiKey: INZXKICQXPWNNE-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
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• 重原子数：
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• 可旋转键数：
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• 环数：
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• sp3杂化的碳原子比例：
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• 拓扑面积：
  None
• 氢给体数：
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• 氢受体数：
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反应信息

• 作为产物：
  描述：

  Na[W(CO)3(cyclopentadienyl)] 、 6-chlorohex-4-yn-3-ol 在 三氟甲磺酸 、 碳酸氢钠 作用下， 以 四氢呋喃 、 二氯甲烷 为溶剂， 以80%的产率得到
  参考文献：
  名称：

  Tungsten-Promoted Intramolecular Alkoxycarbonylation for Synthesis of Complex Oxygenated Molecules

  摘要：

  Intramolecular alkoxycarbonylation of tungsten-propargyl compounds proceeds with excellent diastereoselectivities to form eta(3)-delta- and -epsilon-lactones but for gamma-lactones. With OSi(t-Bu)Me(2) substituted for an or-hydroxy group, eta(3)-gamma-lactones are stereoselectively formed with syn stereoselection. An optically active tungsten eta(3)-gamma-lactone is prepared from D-(+)-xylose to illustrate the stereochemical effect of OSi(t-Bu)Me(2). All these eta(3)-gamma-, -delta-, and -epsilon-lactones are converted to allyl anions that react in situ with aldehydes and ketones to produce various beta-(hydroxylalkyl)-alpha-methylene-gamma-lactones with good diastereoselectivity. This reaction is also applied to the synthesis of chiral alpha-methylene butyrolactones. Organic carbonyls add to the pi-allyl groups of eta(3)-gamma- and -delta-lactones opposite the tungsten fragment, whereas additions occur from the metal side for eta(3)-epsilon-lactones. The stereochemical courses of these reactions are discussed in detail. These two tungsten-promoted reactions efficiently effect stereoselective transformation of chloroalkynols to complex alpha-methylene-gamma-lactones, which are useful materials for syntheses of trisubstituted 1,3-, 1,4-, and 1-5-diols.

  DOI：

  10.1021/ja9617808

文献信息

• Siloxy Effect on Intramolecular Cyclization of Tungsten−η¹-Siloxypropargyl Complexes:  Formation of 2,5-Dihydrofurans versus γ-Lactones
  作者：Shwu-Ju Shieh、Jang-Shyang Fan、Malapaka Chandrasekharam、Fen-Ling Liao、Sue-Lein Wang、Rai-Shung Liu

  DOI：10.1021/om970335y

  日期：1997.9.1

  Treatment of tungsten-eta(1)-4-(triethylsiloxy)propargyl and eta(1)-4-(tripropylsiloxy)propargyl compounds 8a-d and 9a-d with CF3CO2H in cold CH2Cl2 yielded a mixture of tungsten eta(1)-2,5-dihydrofurans 10a-d and eta(3)-syn-gamma-lactones 4a-d. The product ratios depend on the types of alkyl and siloxy substituents of the propargyl ligand; eta(1)-2,5-dihydrofurans 10a-d were formed in significant amount when the substituent is a secondary alkyl group. This cyclization pathway is in sharp contrast to our previous report that the dimethyl-tert-butylsiloxy group yielded only eta(3)-syn-gamma-lactones 4a-d. To validate this reaction on a complex system, we prepared the chiral tungsten-eta(1)-4-(triethylsiloxy)propargyl species 12b, which ultimately gave optically active tungsten eta(1)-2,5-dihydrofuran 13 in 68% yields. in connection with our previous report, we elaborated three types of cyclization reactions on chiral tungsten eta(1)-propargylic triols 12a-c, to afford chiral eta(1)-2,5-dihydrofurans and unsaturated gamma-and delta-lactones in reasonable yields.