Acetic Acid → (2R,3R,4R,5S)-4,5-bis(Acetoxy)-2-(5-ethyl-1,2,4-oxadiazol-3-yl)tetrahydro-3-furanyl Acetate

HRID 1168307Notes

Reaction equation

HRID 1168307 reaction equation
[C:1]([OH:4])(=[O:3])[CH3:2].[C:5]([O:8][C:9](=[O:11])[CH3:10])(=[O:7])[CH3:6].[CH2:12]([C:14]1[O:18][N:17]=[C:16]([C@@H:19]2[C@@H:23](O)[C@@H](O)[C@H](OC)O2)[N:15]=1)[CH3:13].C(C1ON=C([C@@H]2[C@@H](O)[C@@H:38](O)[C@@H:37]([O:42]C)[O:36]2)N=1)C.C(=O)([O-])O.[Na+]>S(=O)(=O)(O)O.ClCCl.C(OCC)C.O>[C:1]([O:4][C@H:23]1[C@@H:6]([O:42][C:37](=[O:36])[CH3:38])[C@H:5]([O:8][C:9](=[O:11])[CH3:10])[O:7][C@@H:19]1[C:16]1[N:15]=[C:14]([CH2:12][CH3:13])[O:18][N:17]=1)(=[O:3])[CH3:2]

Participants

10

Reactant 5

HCID 176Acetic AcidHCID 7918Acetic AnhydrideHCID 516892Sodium BicarbonateHCID 69976962(2R,3S,4R,5S)-2-(5-ethyl-1,2,4-oxadiazol-3-yl)-5-methoxytetrahydro-3,4-furandiolHCID 70023190(2R,3S,4R,5R)-2-(5-ethyl-1,2,4-oxadiazol-3-yl)-5-methoxytetrahydro-3,4-furandiol

Product 1

HCID 59094504(2R,3R,4R,5S)-4,5-bis(Acetoxy)-2-(5-ethyl-1,2,4-oxadiazol-3-yl)tetrahydro-3-furanyl Acetate

Reagents, catalysts & solvents 4

HCID 1118Sulfuric AcidCatalystHCID 962WaterSolventHCID 3283Diethyl EtherSolventHCID 6344DichloromethaneSolvent

Procedure

Acetic acid (1.0 ml, 17.5 mmol), acetic anhydride (1.65 ml, 17.5 mmol) and concentrated sulphuric acid (1 drop) were added to a solution of (2R,3S,4R,5R)-2-(5-ethyl-1,2,4-oxadiazol-3-yl)-5-methoxytetrahydro-3,4-furandiol and (2R,3S,4R,5S)-2-(5-ethyl-1,2,4-oxadiazol-3-yl)-5-methoxytetrahydro-3,4-furandiol (Preparation 37) (0.675 g, 2.93 mmol) in dichloromethane (15 ml) and the solution was heated under reflux for 12 hours. The cooled reaction mixture was then diluted with diethyl ether (30 ml) and water (20 ml). Solid sodium hydrogencarbonate was added to neutralise the solution and the organic layer was separated. The aqueous layer was extracted with more diethyl ether (50 ml) and the combined organic extracts were dried (anhydrous magnesium sulphate) and evaporated under reduced pressure. The semi-crystalline residue was triturated with a mixture of diethyl ether and pentane and the solid was filtered off and dried (0.56 g).

Workup

  1. temperaturethe solution was heated
  2. temperatureunder reflux for 12 hours
  3. customThe cooled reaction mixture
  4. customthe organic layer was separated
  5. extractionThe aqueous layer was extracted with more diethyl ether (50 ml)
  6. dry with materialthe combined organic extracts were dried (anhydrous magnesium sulphate)
  7. customevaporated under reduced pressure
  8. customThe semi-crystalline residue was triturated with a mixture of diethyl ether and pentane
  9. filtrationthe solid was filtered off
  10. customdried (0.56 g)

Sources & evidence

ORD record
ord-cf44c964fc384afd8d1e0d22927f6e5f
Source dataset
uspto-grants-2003_09
Patent number
US06624158B2

Reaction notes

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