Ethanol → (5R,9R)-2-acetyl-5,9,13-trimethyltetradecanoic acid ethyl ester

HRID 1659827Notes

Reaction equation

HRID 1659827 reaction equation
[CH2:1]([O:3][C:4](=[O:6])[CH3:5])[CH3:2].Br[CH2:8][CH2:9][C@H:10]([CH3:22])[CH2:11][CH2:12][CH2:13][C@H:14]([CH3:21])[CH2:15][CH2:16][CH2:17][CH:18]([CH3:20])[CH3:19].[CH2:23]([OH:25])[CH3:24]>>[CH2:1]([O:3][C:4](=[O:6])[CH:5]([C:23](=[O:25])[CH3:24])[CH2:8][CH2:9][C@H:10]([CH3:22])[CH2:11][CH2:12][CH2:13][C@H:14]([CH3:21])[CH2:15][CH2:16][CH2:17][CH:18]([CH3:20])[CH3:19])[CH3:2]

Participants

4

Reactant 3

HCID 702EthanolHCID 8857Ethyl AcetateHCID 13191851(3R,7R)-1-bromo-3,7,11-trimethyldodecane

Product 1

HCID 53870237(5R,9R)-2-acetyl-5,9,13-trimethyltetradecanoic acid ethyl ester

Procedure

To 2.3 ml of a solution of 1.01-N sodium ethylate in ethanol in a flask provided with reflux condenser and calcium chloride tube are added dropwise 300 mg (2.3 mmol) of acetic acid ethyl ester and subsequently 671 mg (2.3 mmol) of (3R,7R)-1-bromo-3,7,11-trimethyldodecane in 2 ml of ethanol. This mixture is boiled under reflux for 15 hours while stirring. After cooling, so much ice water is added that the separated salt is just dissolved, the organic phase is separated in a separating funnel and shaken out four times with methylene chloride. After drying the combined organic phases over magnesium sulphate and distillation of the solvent, there are obtained 755 mg of crude (5R,9R)-2-acetyl-5,9,13-trimethyltetradecanoic acid ethyl ester. For analytical purposes a sample of the crude (5R,9R)-2-acetyl-5,9,13-trimethyl-tetradecanoic acid ethyl ester is chromatographed on a preparative silicagel plate with toluene/hexane/acetic acid ethyl ester=30:10:3 and the thus obtained pure (5R,9R)-2-acetyl-5,9,13-trimethyl-tetradecanoic acid ethyl ester is distilled at 150°/0.03 Torr; [α]36520 =-4.0° (c=1.04; CHCl3).

Workup

  1. temperaturewith reflux condenser and calcium chloride tube
  2. temperatureunder reflux for 15 hours
  3. temperatureAfter cooling
  4. dissolutionis just dissolved
  5. customthe organic phase is separated in a separating funnel
  6. stirringshaken out four times with methylene chloride
  7. customAfter drying the combined organic phases
  8. distillationover magnesium sulphate and distillation of the solvent, there

Sources & evidence

ORD record
ord-b150e02e84f44e70a5889594df0b54d4
Source dataset
uspto-grants-1981_12
Patent number
US04305876

Reaction notes

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