Potassium Carbonate → Carbamic acid, [(1R,4R)-4-hydroxy-2-cyclohexen-1-yl]-, 1,1-dimethylethyl ester, rel-

HRID 1624275Notes

Reaction equation

HRID 1624275 reaction equation
C([O:4][C@H:5]1[CH2:10][CH2:9][C@H:8]([NH:11][C:12]([O:14][C:15]([CH3:18])([CH3:17])[CH3:16])=[O:13])[CH:7]=[CH:6]1)(=O)C.C([O-])([O-])=O.[K+].[K+]>CO>[OH:4][C@H:5]1[CH2:10][CH2:9][C@H:8]([NH:11][C:12]([O:14][C:15]([CH3:18])([CH3:17])[CH3:16])=[O:13])[CH:7]=[CH:6]1

Participants

4

Procedure

To a solution of trans-1-acetoxy-4-(tert-butoxycarbonylamino)-2-cyclohexene (6.70 g, 26.3 mmol) in methanol (130 mL) was added solid K2CO3 (7.50 g, 54.4 mmol) and the mixture was stirred at room temperature for 1 hour. The reaction mixture was concentrated and the residue was dissolved in CH2Cl2 (250 mL) and saturated aqueous NaHCO3 (100 mL). The phases were separated and the aqueous phase was extracted with CH2Cl2 (3×50 mL). The combined organic extracts were dried (Na2SO4) and concentrated. Purification of the crude material by column chromatography on silica gel (20:1 CH2Cl2—CH3OH) provided 3.38 g (60%) of trans-1-hydroxy-4-(tert-butoxycarbonylamino)-2-cyclohexene as a white solid. 1H NMR (CDCl3) δ 1.44 (s, 9H), 1.52-1.57 (m, 1H), 2.05-2.14 (m, 3H), 4.20-4.26 (br s, 2H), 4.45 (br s, 1H), 4.47-4.60 (m, 1H), 5.70 (d, 1H, J=10.2 Hz), 5.81 (d, 1H, J=10.2 Hz);

Workup

  1. concentrationThe reaction mixture was concentrated
  2. dissolutionthe residue was dissolved in CH2Cl2 (250 mL)
  3. customThe phases were separated
  4. extractionthe aqueous phase was extracted with CH2Cl2 (3×50 mL)
  5. dry with materialThe combined organic extracts were dried (Na2SO4)
  6. concentrationconcentrated
  7. customPurification of the crude material by column chromatography on silica gel (20:1 CH2Cl2—CH3OH)

Sources & evidence

ORD record
ord-f2c9b3356cc44ebeb71e8ac60520b9a5
Source dataset
uspto-grants-2014_07
Patent number
US08778967B2

Reaction notes

Loading…