20-(1,3-Dioxolan-2-yl)-1alpha-acetoxy-3beta-(methoxymethyl)oxypregna-5,7-diene → 1alpha-Acetoxy-3beta-(methoxymethyl)oxypregna-5,7-diene-20carbaldehyde
Reaction equation
[O:1]1CCO[CH:2]1[CH:6]([C@@H:8]1[C@:25]2([CH3:26])[C@H:11]([C:12]3[C@H:22]([CH2:23][CH2:24]2)[C@:20]2([CH3:21])[C:15]([CH2:16][C@@H:17]([O:31][CH2:32][O:33][CH3:34])[CH2:18][C@@H:19]2[O:27][C:28](=[O:30])[CH3:29])=[CH:14][CH:13]=3)[CH2:10][CH2:9]1)[CH3:7]>CC(C)=O.Cl(O)(=O)(=O)=O>[C:28]([O:27][C@@H:19]1[C@@:20]2([CH3:21])[C:15](=[CH:14][CH:13]=[C:12]3[C@@H:22]2[CH2:23][CH2:24][C@@:25]2([CH3:26])[C@H:11]3[CH2:10][CH2:9][C@@H:8]2[CH:6]([CH:2]=[O:1])[CH3:7])[CH2:16][C@@H:17]([O:31][CH2:32][O:33][CH3:34])[CH2:18]1)(=[O:30])[CH3:29]Participants
4
Procedure
In 10 ml of acetone was dissolved 100 mg of 20-(1,3-dioxolan-2-yl)-1α-acetoxy-3β-(methoxymethyl)oxypregna-5,7-diene, followed by addition of one drop of 70% perchloric acid, and the mixture was refluxed in an atmosphere of argon gas for 2 hours. The reaction mixture was then worked up in the same manner as Example 156 to give 40 mg of 1α-acetoxy-3β-(methoxymethyl)oxypregna-5,7-diene-20-carbaldehyde showing the following physical properties.