Trimethyl orthoformate → Tert-butyl 3,3-dimethoxycyclopentanecarboxylate

HRID 643522ノート

反応式

HRID 643522 の反応式
O=[C:2]1C[CH2:5][CH:4]([C:7]([O:9][C:10]([CH3:13])([CH3:12])[CH3:11])=[O:8])[CH2:3]1.CO[CH:16]([O:19][CH3:20])[O:17][CH3:18].CC1C=CC(S(O)(=O)=O)=CC=1.O>C(Cl)Cl.CO>[CH3:20][O:19][C:16]1([O:17][CH3:18])[CH2:2][CH2:3][CH:4]([C:7]([O:9][C:10]([CH3:12])([CH3:11])[CH3:13])=[O:8])[CH2:5]1

参加物

5

反応物 3

HCID 9005Trimethyl orthoformateHCID 521998p-Toluenesulfonic acid monohydrate2 回HCID 14009986tert-Butyl 3-oxocyclopentane-1-carboxylate

生成物 1

HCID 58784445Tert-butyl 3,3-dimethoxycyclopentanecarboxylate

試薬・触媒・溶媒 1

HCID 21226129Dichloromethane methanol溶媒

実験手順

To a solution of tert-butyl 3-oxocyclopentanecarboxylate (19.8 g, 107 mmol) in 1:1 DCM/methanol (150 mL) was added trimethylorthoformate (46.8 mL, 428 mmol), followed by TsOH.H2O (˜0.5 g). The reaction mixture was stirred at rt for 2 h. Then more TsOH.H2O (˜0.25 g) was added and the reaction mixture was stirred overnight. The reaction mixture was concentrated at rt and the resulting residue was dissolved in ether and washed with saturated NaHCO3 solution, then with brine. The ethereal layer was dried over anhydrous MgSO4, filtered, and concentrated. Purification by flash chromatography (silica, 15% ethyl acetate/hexane) gave tert-butyl 3,3-dimethoxycyclopentanecarboxylate. 1H NMR (500 MHz, CDCl3): 3.21 (s, 3H), 3.20 (s, 3H), 2.80 (m, 1H), 2.10 to 1.80 (bm, 6H), 1.46 (s, 9H). 13C NMR (125 MHz, CDCl3): 174.9, 111.2, 80.3, 67.8, 49.2, 42.5, 37.4, 33.8, 28.3, 22.0.

後処理

  1. stirringthe reaction mixture was stirred overnight
  2. concentrationThe reaction mixture was concentrated at rt
  3. dissolutionthe resulting residue was dissolved in ether
  4. washwashed with saturated NaHCO3 solution
  5. dry with materialThe ethereal layer was dried over anhydrous MgSO4
  6. filtrationfiltered
  7. concentrationconcentrated
  8. customPurification by flash chromatography (silica, 15% ethyl acetate/hexane)

出典と根拠

ORDレコード
ord-3770f833ad154dd092274b232c7d66f5
出典データセット
uspto-grants-2010_04
特許番号
US07700591B2

反応ノート

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