三氯甲烷 → 3-Acetoxy-5-t-butyldimethylsiloxycyclopent-1-ene

HRID 2549

反应方程式

HRID 2549 反应方程式
[Si:1]([O:8][C@@H:9]1[CH2:13][C@H:12]([OH:14])[CH:11]=[CH:10]1)([C:4]([CH3:7])([CH3:6])[CH3:5])([CH3:3])[CH3:2].C(N(CC)CC)C.[C:22](OC=C)(=[O:24])[CH3:23].C(Cl)(Cl)Cl>COC(C)(C)C>[Si:1]([O:8][CH:9]1[CH2:13][CH:12]([O:14][C:22](=[O:24])[CH3:23])[CH:11]=[CH:10]1)([C:4]([CH3:7])([CH3:6])[CH3:5])([CH3:3])[CH3:2]

参与物

6

反应物 4

HCID 6212三氯甲烷2 次HCID 7904乙酸乙烯酯HCID 8471三乙胺HCID 101767472-Cyclopenten-1-ol, 4-[[(1,1-dimethylethyl)dimethylsilyl]oxy]-, cis-2 次

产物 1

HCID 127633543-Acetoxy-5-t-butyldimethylsiloxycyclopent-1-ene收率 51.1%

试剂、催化剂与溶剂 1

HCID 15413甲基叔丁基醚溶剂

实验过程

Cis-4-tert-butyldimethylsilyloxy-2-cyclopentenol (10.0 g, 46.6 mmol, prepared in example 3a) is dissolved in tert-butyl methyl ether (60 mL, anhydrous). To the solution is added triethylamine (4.5 mL, 32.3 mmol), pancreatin (30 g, available from Sigma Chemical Company), and vinyl acetate (22 mL, 239 mmol). The reaction is allowed to stir for 7 hours at room temperature. The reaction is then filtered through diatomaceous earth and the filtrate is concentrated under vacuum. The products are separated by chromatography on silica gel (5% to 20% ethyl acetate/hexane) to provide (-)-acetic acid 4-tert-butyldimethylsilyloxy-cyclopent-2-enyl ester (B, 6.1 g, 51% yield, 99% ee), [α]D -0.2°, (c=0.52, chloroform) as a yellow oil and (-)-cis-4-tert-butyldimethylsilyloxy-2-cyclopentenol (A, 4.7 g, 47% yield, >99% ee), [α]D -18.6°, (c=1.01, chloroform) as a yellow oil.

后处理

  1. filtrationThe reaction is then filtered through diatomaceous earth
  2. concentrationthe filtrate is concentrated under vacuum
  3. customThe products are separated by chromatography on silica gel (5% to 20% ethyl acetate/hexane)

来源与证据

ORD记录
ord-4080122b276c4fa69f2e3e82eeb5a920
来源数据集
uspto-grants-1998_03
专利号
US05728899

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