(25R)-16beta-HYDROXY-26-PHTHALIMIDOCHOLESTEROL → (25R)-16-oxo-26-phthalimidocholesterol
Reaktionsgleichung
C1(=O)NC(=O)C2=CC=CC=C12.[K].[OH:13][C@H:14]1[CH2:49][C@@H:48]2[C@:35]([CH3:52])([CH2:36][CH2:37][C@H:38]3[C@H:47]2[CH2:46][CH:45]=[C:44]2[C@:39]3([CH3:51])[CH2:40][CH2:41][C@H:42]([OH:50])[CH2:43]2)[C@H:15]1[C@H:16]([CH3:34])[CH2:17][CH2:18][CH2:19][C@@H:20]([CH3:33])[CH2:21][N:22]1[C:26](=[O:27])[C:25]2=[CH:28][CH:29]=[CH:30][CH:31]=[C:24]2[C:23]1=[O:32]>>[O:13]=[C:14]1[CH2:49][C@@H:48]2[C@:35]([CH3:52])([CH2:36][CH2:37][C@H:38]3[C@H:47]2[CH2:46][CH:45]=[C:44]2[C@:39]3([CH3:51])[CH2:40][CH2:41][C@H:42]([OH:50])[CH2:43]2)[C@H:15]1[C@H:16]([CH3:34])[CH2:17][CH2:18][CH2:19][C@@H:20]([CH3:33])[CH2:21][N:22]1[C:23](=[O:32])[C:24]2=[CH:31][CH:30]=[CH:29][CH:28]=[C:25]2[C:26]1=[O:27]Komponenten
3
Versuchsvorschrift
According to Scheme 1, (25R)-16β-26-dihydroxycholesterol (2), prepared in one step from diosgenin, is selectively reacted at the C-26 hydroxyl group with p-toluene sulfonyl chloride to yield (25R)-16β-26-dihydroxycholesterol 26-tosylate (3) which is then reacted with potassium phthalimide. The resulting (25R)-16β-hydroxy-26-phthalimidocholesterol (4) is then subjected to a modified Jones oxidation which selectively oxidizes the 16β hydroxy group to form (25R)-16-oxo-26-phthalimidocholesterol (5).
Quellen und Nachweise
- ORD-Eintrag