Trifluoroacetic acid → (2-Ethoxy-5-oxo-tetrahydrofuran-3-yl)-carbamic acid allyl ester

HRID 722739Notes

Reaction equation

HRID 722739 reaction equation
C(O[C:6](=[O:23])[CH2:7][CH:8]([NH:16][C:17]([O:19][CH2:20][CH:21]=[CH2:22])=[O:18])[CH:9]([O:13]CC)[O:10][CH2:11][CH3:12])(C)(C)C.FC(F)(F)C(O)=O>C(Cl)Cl>[CH2:20]([O:19][C:17](=[O:18])[NH:16][CH:8]1[CH2:7][C:6](=[O:23])[O:13][CH:9]1[O:10][CH2:11][CH3:12])[CH:21]=[CH2:22]

Participants

4

Reactant 2

HCID 6422Trifluoroacetic acidHCID 235987123-Allyloxycarbonylamino-4,4-diethoxy-butyric acid tert-butyl ester

Product 1

HCID 22149038(2-Ethoxy-5-oxo-tetrahydrofuran-3-yl)-carbamic acid allyl esterYield 85%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

A solution of the crude 3-Allyloxycarbonylamino-4,4-diethoxy-butyric acid tert-butyl ester, 103, obtained in the procedure above, in CH2Cl2(50 mL) is treated with triflouroacetic acid (50 mL). After the consumption of starting material, the organics are reduced under vacuum. The residual triflouroacetic acid is removed with ethyl acetate by azeotroping conditions. The final residue is purified over silica (hexanes/ethyl acetate 80:20) to afford 10.1 g (85% yield) of the desired product as a slightly yellow oil. 1H-NMR, (300 MHz, CDCl3): δ 1.23 (m, 3H), 2.41–2.54 (m, 1H), 2.82–3.06 (m, 2H), 3.61–3.73 (m, 1H), 3.82–3.98 (m, 1H), 4.06–4.25 (m, 1H), 4.61 (br s, 2H), 5.24–5.53 (m, 3H), 5.86–6.01 (m, 1H); MS (ESI): m/e=230.03 (M+H).

Workup

  1. customAfter the consumption of starting material
  2. customThe residual triflouroacetic acid is removed with ethyl acetate
  3. customby azeotroping conditions
  4. customThe final residue is purified over silica (hexanes/ethyl acetate 80:20)

Sources & evidence

ORD record
ord-ba5946328c7647a2bb4168db7094ef61
Source dataset
uspto-grants-2006_11
Patent number
US07138395B2

Reaction notes

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