乙酸乙烯酯 → (lR,3S)-(+)-3-tert-butyldimethylsilyloxycyclopentanyl acetate

HRID 2566

反应方程式

HRID 2566 反应方程式
[Si:1]([O:8][C@@H:9]1[CH2:13][CH2:12][C@H:11]([OH:14])[CH2:10]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]>COC(C)(C)C>[C:22]([O:14][C@@H:11]1[CH2:12][CH2:13][C@H:9]([O:8][Si:1]([C:4]([CH3:7])([CH3:6])[CH3:5])([CH3:3])[CH3:2])[CH2:10]1)(=[O:24])[CH3:23]

参与物

5

反应物 3

HCID 7904乙酸乙烯酯HCID 8471三乙胺HCID 54118351(1S,3R)-3-{[tert-Butyl(dimethyl)silyl]oxy}cyclopentan-1-ol

产物 1

HCID 54211622(lR,3S)-(+)-3-tert-butyldimethylsilyloxycyclopentanyl acetate收率 49%

试剂、催化剂与溶剂 1

HCID 15413甲基叔丁基醚溶剂

实验过程

Combine (+/-)-cis-3-tert-butyldimethylsilyloxycyclopentanol (2.119 g, 9.8 mmol, prepared in example 29), pancreatin (6.2 g, 3 weight equivalents), triethylamine (0.9 mL, 6.5 mmol) and vinyl acetate (4.3 mL) in tert-butyl methyl ether (12 mL) and stir for 27 hours at room temperature. Then filter the reaction through diatomaceous earth and concentrate the filtrate under vacuum (room temperature/15 mmHg). Purify the residue by column chromatography [silica gel, 55 g, hexane (300 mL) followed by 5% ethyl acetate/hexane (500 mL)] to provide the (1R,3S)-(+)-3-tert-butyldimethylsilyloxycyclopentanyl acetate (1.23 g, 49% yield, 98% ee as determined from gas chromatography with a chiral column) and (1S,3R)-(-)-3-tert-butyldimethylsilyloxycyclopentanol (771 mg, 37% yield, 92% ee as determined from its acetate derivative followed by GC chiral column analysis, see example 30a).

后处理

  1. filtrationThen filter
  2. customthe reaction through diatomaceous earth
  3. concentrationconcentrate the filtrate under vacuum (room temperature/15 mmHg)
  4. customPurify the residue by column chromatography [silica gel, 55 g, hexane (300 mL) followed by 5% ethyl acetate/hexane (500 mL)]

来源与证据

ORD记录
ord-b1dad0bf641048d099cfa0228402d3a6
来源数据集
uspto-grants-1998_03
专利号
US05728899

关联笔记

加载中…