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

HRID 643540Notizen

Reaktionsgleichung

Reaktionsgleichung von HRID 643540
[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]

Komponenten

6

Edukt 4

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

Produkt 1

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

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 8028TetrahydrofuranLösungsmittel2×

Reaktionsbedingungen

Temperatur
-78 °C

Versuchsvorschrift

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.

Aufarbeitung

  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)

Quellen und Nachweise

ORD-Eintrag
ord-3fa2a303db0045ab8ca2f0760a8d3216
Quelldatensatz
uspto-grants-2010_04
Patentnummer
US07700591B2

Notizen zur Reaktion

Wird geladen…