Acetic Acid → [(1S)-1-[(2S,4R,5R)-4,5-diacetoxytetrahydrofuran-2-yl]propyl] 2-methylpropanoate

HRID 60772Notes

Reaction equation

HRID 60772 reaction equation
[CH3:1][CH:2]([CH3:19])[C:3]([O:5][C@H:6]([C@H:9]1[O:18][C@@H:12]2[O:13][C:14]([CH3:17])(C)[O:15][C@@H:11]2[CH2:10]1)[CH2:7][CH3:8])=[O:4].[C:20]([O:23]C(=O)C)(=[O:22])[CH3:21].C(O)(=O)C.S(=O)(=O)(O)O>C(Cl)Cl>[CH3:19][CH:2]([CH3:1])[C:3]([O:5][C@H:6]([C@@H:9]1[CH2:10][C@@H:11]([O:15][C:14](=[O:13])[CH3:17])[C@@H:12]([O:23][C:20](=[O:22])[CH3:21])[O:18]1)[CH2:7][CH3:8])=[O:4]

Participants

6

Reactant 4

HCID 176Acetic AcidHCID 1118Sulfuric AcidHCID 7918Acetic AnhydrideHCID 121396299[(1S)-1-[(3aR,5S,6aR)-2,2-dimethyl-3a,5,6,6a-tetrahydrofuro[2,3-d][1,3]dioxol-5-yl]propyl] 2-methylpropanoate2×

Product 1

HCID 121396294[(1S)-1-[(2S,4R,5R)-4,5-diacetoxytetrahydrofuran-2-yl]propyl] 2-methylpropanoateYield 19.2%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

To a stirred solution of [(1S)-1-[(3aR,5S,6aR)-2,2-dimethyl-3a,5,6,6a-tetrahydrofuro[2,3-d][1,3]dioxol-5-yl]propyl] 2-methylpropanoate (compound 42a, 470 mg, 1.73 mmol), acetic anhydride (0.81 mL, 8.64 mmol) and acetic acid (0.51 mL, 8.64 mmol) in DCM (10 mL) was added concentrated sulfuric acid (18.4 μL, 0.17 mmol). The resulting mixture was stirred at room temperature overnight. The resulting mixture was concentrated in vacuo. The residue was purified by column chromatography on silica gel (eluting with 0-20% EtOAc in petroleum ether) to afford 105 mg of [(1S)-1-[(2S,4R,5R)-4,5-diacetoxytetrahydrofuran-2-yl]propyl] 2-methylpropanoate (compound 42b).

Workup

  1. concentrationThe resulting mixture was concentrated in vacuo
  2. customThe residue was purified by column chromatography on silica gel (eluting with 0-20% EtOAc in petroleum ether)

Sources & evidence

ORD record
ord-6523d6c2540943e98b6bd38661829937
Source dataset
uspto-grants-2016_09
Patent number
US09441008B2

Reaction notes

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