Acetaldehyde → Tert-butyl 1-(1-hydroxyethyl)-3,3-dimethoxycyclopentanecarboxylate

HRID 643540ノート

反応式

HRID 643540 の反応式
[Li+].CC([N-]C(C)C)C.[CH3:9][O:10][C:11]1([O:23][CH3:24])[CH2:15][CH2:14][CH:13]([C:16]([O:18][C:19]([CH3:22])([CH3:21])[CH3:20])=[O:17])[CH2:12]1.[CH:25](=[O:27])[CH3:26].C(O)(=O)CC(CC(O)=O)(C(O)=O)O>C1COCC1>[OH:27][CH:25]([C:13]1([C:16]([O:18][C:19]([CH3:20])([CH3:21])[CH3:22])=[O:17])[CH2:14][CH2:15][C:11]([O:23][CH3:24])([O:10][CH3:9])[CH2:12]1)[CH3:26]

参加物

6

反応物 4

HCID 177AcetaldehydeHCID 311Citric AcidHCID 2724682Lithium diisopropylamideHCID 58784445Tert-butyl 3,3-dimethoxycyclopentanecarboxylate

生成物 1

HCID 57880496Tert-butyl 1-(1-hydroxyethyl)-3,3-dimethoxycyclopentanecarboxylate

試薬・触媒・溶媒 1

HCID 8028Tetrahydrofuran溶媒2 回

反応条件

温度
-78 °C

実験手順

To a cooled (−78° C.) solution of LDA (2M in THF/heptane, 39 mL, 78 mmol) in THF (40 mL) was added dropwise over 15 min tert-butyl 3,3-dimethoxycyclopentanecarboxylate (15.0 g, 65.0 mmol) in 100 mL of THF. The resulting mixture was stirred at −78° C. for 40 min, then was treated dropwise with acetaldehyde (7.27 mL, 130 mmol). After stirring for an additional 45 min, the reaction mixture was poured into 500 mL of 10% citric acid solution. The mixture was extracted twice with ether and the combined ethereal layers were washed with brine. The ethereal layer was then dried over anhydrous MgSO4, filtered, and concentrated. TLC analysis indicated that the reaction had not gone to completion and a considerable amount of starting material was still present. Purification/separation by flash chromatography (silica, 30% ethyl acetateihexane) gave the tert-butyl 1-(1-hydroxyethyl)-3,3-dimethoxycyclopentanecarboxylate as an approximately 1:1 ratio of threo and erythro diastereomer pairs and recovered tert-butyl 3,3-dimethoxycyclopentanecarboxylate.

後処理

  1. stirringAfter stirring for an additional 45 min
  2. extractionThe mixture was extracted twice with ether
  3. washthe combined ethereal layers were washed with brine
  4. dry with materialThe ethereal layer was then dried over anhydrous MgSO4
  5. filtrationfiltered
  6. concentrationconcentrated
  7. customPurification/separation by flash chromatography (silica, 30% ethyl acetateihexane)

出典と根拠

ORDレコード
ord-3fa2a303db0045ab8ca2f0760a8d3216
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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