Potassium Carbonate → Carbamic acid, [(1R,4R)-4-hydroxy-2-cyclohexen-1-yl]-, 1,1-dimethylethyl ester, rel-
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]1Participants
Reactant 2
Product 1
Reagents, catalysts & solvents 1
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
- concentrationThe reaction mixture was concentrated
- dissolutionthe residue was dissolved in CH2Cl2 (250 mL)
- customThe phases were separated
- extractionthe aqueous phase was extracted with CH2Cl2 (3×50 mL)
- dry with materialThe combined organic extracts were dried (Na2SO4)
- concentrationconcentrated
- customPurification of the crude material by column chromatography on silica gel (20:1 CH2Cl2—CH3OH)
Sources & evidence
- ORD record
- ord-9f4fd98823ed4bc38e0ce0d337611079
- Source dataset
- uspto-grants-2008_04
- Patent number
- US07354934B2
Reaction notes
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