Boron trifluoride etherate → 4-Tert-butoxy-cyclopent-2-enone

HRID 2547

反応式

HRID 2547 の反応式
[OH:1][CH:2]1[CH2:6][C:5](=[O:7])[CH:4]=[CH:3]1.ClC(Cl)(Cl)C(=N)O[C:12]([CH3:15])([CH3:14])[CH3:13].B(F)(F)F.CCOCC.C(=O)(O)[O-].[Na+]>C(Cl)Cl>[C:12]([O:7][CH:5]1[CH2:6][C:2](=[O:1])[CH:3]=[CH:4]1)([CH3:15])([CH3:14])[CH3:13]

参加物

6

反応物 4

HCID 8000Boron trifluoride etherateHCID 516892Sodium BicarbonateHCID 2734700Tert-butyl 2,2,2-trichloroethanimidateHCID 41691604-Hydroxycyclopent-2-en-1-one

生成物 1

HCID 110625964-Tert-butoxy-cyclopent-2-enone収率 40%

試薬・触媒・溶媒 1

HCID 6344Dichloromethane溶媒

反応条件

温度
6.5 °C

実験手順

A solution of 4-hydroxy-2-cyclopentenone (1.15 g, 11.7 mmol) in methylene chloride is cooled to 3° C. and treated sequentially with tert-butyl trichloroacetimidate (4.2 mL, 23.7 mmol) and boron trifluoride diethyl etherate (0.15 mL). The reaction mixture is stirred at 3-10° C. for 2 hours and then allowed to warm to room temperature and stirred for 22 hours. The reaction mixture is then treated with sodium bicarbonate (250 mg) and filtered. The filtrate is concentrated under vacuum and the residue is purified by chromatography (silica gel, 39 g, 20% ethyl acetate/hexane, 600 mL) to provide the title compound (355 mg, 40%) as a yellow oil; 1H NMR (CDCl3)δ7.44 (dd, 1H, J=18 Hz), 6.2 (d, 1H, J=5.4 Hz), 4.8 (m, 1H), 2.68 (dd, 1H, J=5.8, 18 Hz), 2.25 (d, 1H, J=18 Hz), 1.27 (s, 9H); IR (neat) νmax 2976, 2936, 1721, 1368, 1352, 1188, 1103, 1161 cm-1 ; MS (CI) m/e (% relative intensity) 155 (M+H+, 22), 99 (100).

後処理

  1. temperatureto warm to room temperature
  2. stirringstirred for 22 hours
  3. filtrationfiltered
  4. concentrationThe filtrate is concentrated under vacuum
  5. customthe residue is purified by chromatography (silica gel, 39 g, 20% ethyl acetate/hexane, 600 mL)

出典と根拠

ORDレコード
ord-46441d6502ac4bf9a6e8aa14f7c747f1
出典データセット
uspto-grants-1998_03
特許番号
US05728899

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