Acetic Anhydride → (5-acetyloxy-1,3-oxathiolan-2-yl)methyl Butanoate

HRID 323902Notes

Reaction equation

HRID 323902 reaction equation
[C:1]([O:6][CH2:7][CH:8]1[S:12][CH2:11][C:10](=[O:13])[O:9]1)(=[O:5])[CH2:2][CH2:3][CH3:4].[H-].[C:15]([O:19][Al](OC(C)(C)C)OC(C)(C)C)(C)(C)[CH3:16].[Li+].C(OC(=O)C)(=O)C.C([O-])(O)=O.[Na+]>C1COCC1.CN(C1C=CN=CC=1)C.CCCCCC.C(OCC)(=O)C>[C:1]([O:6][CH2:7][CH:8]1[S:12][CH2:11][CH:10]([O:13][C:15](=[O:19])[CH3:16])[O:9]1)(=[O:5])[CH2:2][CH2:3][CH3:4]

Participants

9

Reactant 4

HCID 7918Acetic AnhydrideHCID 516892Sodium BicarbonateHCID 11206498(5-oxo-1,3-oxathiolan-2-yl)methyl ButanoateHCID 16710494Lithium tri-tert-butoxyaluminohydride

Product 1

HCID 11379646(5-acetyloxy-1,3-oxathiolan-2-yl)methyl ButanoateYield 80%

Reagents, catalysts & solvents 4

HCID 142844-(Dimethylamino)pyridineCatalystHCID 8028TetrahydrofuranSolvent2×HCID 8058HexaneSolventHCID 8857Ethyl AcetateSolvent

Conditions

Temperature
-7.5 °C

Procedure

To a solution of 25 (0.50 g, 2.5 mmol) in anhydrous THF (15 ml) at −5 to −10° C., a solution of 1.0 M lithium tri-t-butoxy aluminum hydride in THF (2.7 ml) was added by syringe pump over 2 hours, while the temperature was maintained at −5 to −10° C. Upon completion of addition, the solution was allowed to stand at 3° C. for 18 hours, and was then warmed to room temperature. DMAP (1.7 mmole, 0.20 g) and acetic anhydride (25.0 mmole, 2.4 ml) were added and the resulting orange solution was stirred at ambient temperature for 3 hours, at which point concentrated NaHCO3 (25 ml) was added. After stirring for 1 hour, the phases were separated, and the aqueous phase was extracted with two additional portions of AcOEt. The organic fractions were combined, dried (MgSO4), filtered and evaporated to afford crude product (0.77 g). After flash chromatography (20 g of silica gel with 20% ethyl acetate in hexane), compound 26 (0.50 g, 2.0 mmol, 80%) was isolated as an oil: TLC (25% ethyl acetate:hexane)—one spot with Rf=0.51; 1H-nmr (CDCl3)—compatible with structure.

Workup

  1. additionUpon completion of addition
  2. temperaturewas then warmed to room temperature
  3. additionwas added
  4. customthe phases were separated
  5. extractionthe aqueous phase was extracted with two additional portions of AcOEt
  6. dry with materialdried (MgSO4)
  7. filtrationfiltered
  8. customevaporated
  9. customto afford crude product (0.77 g)

Sources & evidence

ORD record
ord-37be38661aac417085920a6d39bd57a6
Source dataset
uspto-grants-2001_04
Patent number
US06215004B1

Reaction notes

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