Benzyl Bromide → (S)-4-Benzyloxy-1,2-butanediol

HRID 1939705Notes

Reaction equation

HRID 1939705 reaction equation
C(C1(C(C)C)[O:8][C@@H:7]([CH2:9][CH2:10][OH:11])[CH2:6][O:5]1)(C)C.[CH2:15](Br)[C:16]1[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=1.[OH-].[Na+]>[I-].C([N+](CCCC)(CCCC)CCCC)CCC>[CH2:15]([O:11][CH2:10][CH2:9][C@H:7]([OH:8])[CH2:6][OH:5])[C:16]1[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=1

Participants

5

Reactant 3

HCID 7498Benzyl BromideHCID 14798Sodium HydroxideHCID 54467051(S)-4-(2-Hydroxyethyl)-2,2-diisopropyl-1,3-dioxolane

Product 1

HCID 9794180(S)-4-Benzyloxy-1,2-butanediolYield 92.3%

Reagents, catalysts & solvents 1

HCID 67553Tetrabutylammonium IodideCatalyst

Conditions

Temperature
110 °C

Procedure

(S)-2,2-Diisopropyl-4-(2-hydroxyethyl)dioxolane (76.2 g, 0.377 mol), benzylbromide (129 g, 0.753 mol) and tetrabutylammonium iodide (7 g, 19 mmol) were mixed with a concentrated sodium hydroxide solution (40 g in 90 mL of water, 2.26 mol) in a 3-neck flask equipped with a mechanic stirrer and a condenser. After stirred at 110° C. for 18 hours, the mixture was cooled to room temperature and the organic layer was separated. The aqueous layer was extracted with methylene chloride (100 mL×2). The combined methylene chloride extrats were dried over magnesium sulfate. The solvent was evaporated, and the residue was treated with 300 mL of 1.5M sulfuric acid. After stirred at 100° C. for 8 hours, the mixture was cooled to room temperature, and hexane (300 mL) was added. The aqueous layer was washed with hexane twice (200 mL×2), and then ajusted pH to 8-9 with concentrated sodium sodium hydroxide. The solution was extrated with ethyl acetate (200 mL×3). The combined ethyl acetate extrates were dried over magnesium sulfate. The solvent was evaporated, and the residue was purified by fractional distillation in vacuo (0.1 mmHg, bp 150°-170° C.) to give 68.3 g (92% yield) of the title compound as an oil.

Workup

  1. customequipped with a mechanic stirrer and a condenser
  2. temperaturethe mixture was cooled to room temperature
  3. customthe organic layer was separated
  4. extractionThe aqueous layer was extracted with methylene chloride (100 mL×2)
  5. dry with materialThe combined methylene chloride extrats were dried over magnesium sulfate
  6. customThe solvent was evaporated
  7. additionthe residue was treated with 300 mL of 1.5M sulfuric acid
  8. stirringAfter stirred at 100° C. for 8 hours
  9. temperaturethe mixture was cooled to room temperature
  10. additionhexane (300 mL) was added
  11. washThe aqueous layer was washed with hexane twice (200 mL×2)
  12. dry with materialThe combined ethyl acetate extrates were dried over magnesium sulfate
  13. customThe solvent was evaporated
  14. distillationthe residue was purified by fractional distillation in vacuo (0.1 mmHg, bp 150°-170° C.)

Sources & evidence

ORD record
ord-e482a6f881814f8e95a21ddcd39d8aa3
Source dataset
uspto-grants-1997_12
Patent number
US05696263

Reaction notes

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