Reaction equation
[CH3:1][C@@H:2]([C@@H:8]1[C@@:12]2([CH3:29])[C@@H:13]([OH:28])[CH2:14][C@@H:15]3[C@@:20]4([CH3:26])[CH2:21][CH2:22][C@@H:23]([OH:25])[CH2:24][C@H:19]4[CH2:18][C@@H:17]([OH:27])[C@H:16]3[C@@H:11]2[CH2:10][CH2:9]1)[CH2:3][CH2:4][C:5]([OH:7])=[O:6].[N+](=[CH2:32])=[N-].CC1C=CC(S(N(N=O)C)(=O)=O)=CC=1>C1COCC1.CCOCC>[CH3:1][C@@H:2]([C@@H:8]1[C@@:12]2([CH3:29])[C@@H:13]([OH:28])[CH2:14][C@@H:15]3[C@@:20]4([CH3:26])[CH2:21][CH2:22][C@@H:23]([OH:25])[CH2:24][C@H:19]4[CH2:18][C@@H:17]([OH:27])[C@H:16]3[C@@H:11]2[CH2:10][CH2:9]1)[CH2:3][CH2:4][C:5]([O:7][CH3:32])=[O:6]Participants
Reactant 3
Product 1
Reagents, catalysts & solvents 2
Procedure
Cholic acid (1a) (2.0 g, 4.9 mmol) in THF (40 ml) at 0° C. was treated dropwise with freshly prepared diazomethane in ether (prepared in the usual manner from diazald: diazald is N-methyl-N-nitroso-p-toluenesulphonamide) until the yellow colour persisted. After 15 minutes at 0° C. the solvent was evaporated to yield a white foam (2.1 g, 100%). Recrystallisation from methanol afforded pure methyl cholate1 (1.3 g, 63%): m.p. 158°-159° C. (crystals began to melt 86°-88° C. and then resolidified--this was probably due to the retention of methanol in the crystals, see NMR data) [Lit1 156°-158° C.]; 1H NMR (60 MHz; CDCl3) δ0.66 (3H, s, 18-CH3), 0.87 (3H, s, 19-CH3), 3.0-3.6 (1H, m. 3β-H), 3.2-3.5 (3H, m [exchanges on adding D2O], 3α, 7α and 12α OH's), 3.48 (s, MeOH of crystallisation [ca. 1 mol equiv.]), 3.65 (3H, s, 24-OMe), 3.7-3.9 (1H, m, 7β-H), 3.8-4.0 (1H, m, 12β-H); IR (nujol mull) 3392, 3300 (OH's), 1734 (C=O) cm-1.
Workup
- customAfter 15 minutes at 0° C. the solvent was evaporated
Sources & evidence
- ORD record
- ord-418cb715e4b147198e9741c3b48d389e
- Source dataset
- uspto-grants-1993_11
- Patent number
- US05266566
Linked notes
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