3,3-dimethoxypentane → HCID 54436966, compound

HRID 2260390Notes

Reaction equation

HRID 2260390 reaction equation
[C:1]([O:5][C:6]([NH:8][C@@H:9]([C:17]1[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=1)[C@@H:10]([OH:16])[C:11]([O:13][CH2:14][CH3:15])=[O:12])=[O:7])([CH3:4])([CH3:3])[CH3:2].CO[C:25](OC)([CH2:28][CH3:29])[CH2:26][CH3:27]>C1(C)C=CC=CC=1.C1(C)C=CC(S([O-])(=O)=O)=CC=1.[NH+]1C=CC=CC=1>[C:1]([O:5][C:6]([N:8]1[C@@H:9]([C:17]2[CH:18]=[CH:19][CH:20]=[CH:21][CH:22]=2)[C@H:10]([C:11]([O:13][CH2:14][CH3:15])=[O:12])[O:16][C:25]1([CH2:28][CH3:29])[CH2:26][CH3:27])=[O:7])([CH3:2])([CH3:3])[CH3:4]

Participants

5

Reactant 2

HCID 99203963,3-dimethoxypentaneHCID 10924911N-(t-Boc)-3-phenyl Isoserine Ethyl Ester

Product 1

HCID 54436966HCID 54436966, compoundYield 75.4%

Reagents, catalysts & solvents 2

HCID 466102Benzenesulfonic acid, 4-methyl-, compd. with pyridine (1:1)CatalystHCID 1140TolueneSolvent

Conditions

Temperature
20 °C

Procedure

A solution of 2.5 g of ethyl (2R,3S)-3-tert-butoxycarbonylamino-2-hydroxy-3-phenylpropionate, 1.12 g of 3,3-dimethoxypentane and 25 mg of pyridinium p-toluene-sulphonate in 25 cm3 of toluene is stirred for 3 hours at a temperature in the region of 20° C. The reaction mixture is heated to boiling and the distillate is collected in a graduated vessel. After 20 cm3 of distillate have been collected, a solution of 1.12 g of 3,3-dimethoxypentane and 25 mg of pyridinium p-toluenesulphonate in 10 cm3 of toluene is added to the reaction medium and the mixture is heated to reflux of the toluene for 5 hours. The reaction medium is cooled to a temperature in the region of 20° C. and 10 cm3 of saturated aqueous sodium hydrogen carbonate solution are then added. The aqueous phase is separated after settling has taken place and then extracted with 2 times 10 cm3 of dichloromethane. The organic phases are combined, dried over magnesium sulphate, filtered and concentrated to dryness under reduced pressure (2.7 kPa) at a temperature in the region of 40° C. 2.3 g of ethyl (4S,5R)-3-tert-butoxycarbonyl-2,2-diethyl-4-phenyl-5-oxazolidinecarboxylate are thereby obtained in the form of a yellow oil.

Workup

  1. temperatureThe reaction mixture is heated
  2. distillationthe distillate is collected in a graduated vessel
  3. distillationAfter 20 cm3 of distillate have been collected
  4. additiona solution of 1.12 g of 3,3-dimethoxypentane and 25 mg of pyridinium p-toluenesulphonate in 10 cm3 of toluene is added to the reaction medium
  5. temperaturethe mixture is heated
  6. temperatureto reflux of the toluene for 5 hours
  7. additionare then added
  8. customThe aqueous phase is separated after settling
  9. extractionextracted with 2 times 10 cm3 of dichloromethane
  10. dry with materialdried over magnesium sulphate
  11. filtrationfiltered
  12. concentrationconcentrated to dryness under reduced pressure (2.7 kPa) at a temperature in the region of 40° C

Sources & evidence

ORD record
ord-312b1995cd7144c9846143f22d0d8964
Source dataset
uspto-grants-1995_12
Patent number
US05476954

Reaction notes

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