Acetic Anhydride → 20-(1,3-Dioxolan-2-yl)-3beta-acetoxypregn-6-ene-1alpha,5alpha-diol
Reaktionsgleichung
[O:1]1[CH2:5][CH2:4][O:3][CH:2]1[CH:6]([C@@H:8]1[C@:25]2([CH3:26])[C@H:11]([C@H:12]3[C@H:22]([CH2:23][CH2:24]2)[C@:20]2([CH3:21])[C@:15]([OH:29])([CH2:16][C@@H:17]([OH:28])[CH2:18][C@@H:19]2[OH:27])[CH:14]=[CH:13]3)[CH2:10][CH2:9]1)[CH3:7].[C:30](OC(=O)C)(=[O:32])[CH3:31]>N1C=CC=CC=1>[O:1]1[CH2:5][CH2:4][O:3][CH:2]1[CH:6]([C@@H:8]1[C@:25]2([CH3:26])[C@H:11]([C@H:12]3[C@H:22]([CH2:23][CH2:24]2)[C@:20]2([CH3:21])[C@:15]([OH:29])([CH2:16][C@@H:17]([O:28][C:30](=[O:32])[CH3:31])[CH2:18][C@@H:19]2[OH:27])[CH:14]=[CH:13]3)[CH2:10][CH2:9]1)[CH3:7]Komponenten
4
Edukt 2
Produkt 1
Reagenzien, Katalysatoren, Lösungsmittel 1
Versuchsvorschrift
In 5 ml of pyridine was dissolved 400 mg of 20-(1,3-dioxolan-2-yl)pregn-6-ene-1α,3β,5α-triol. To this solution was added 0.11 ml of acetic anhydride at a temperature of -10°-0° C. and the mixture was stirred under ice-cooling for 2 hours. The reaction mixture thus obtained was poured in ice-water and stirred at room temperature for 30 minutes. This mixture was then extracted with ether and the extracts were pooled, washed successively with water, cold diluted hydrochloric acid, water, aqueous sodium hydrogen carbonate solution and aqueous sodium chloride solution and dried over magnesium sulfate, followed by concentration under reduced pressure. Finally the concentrate was purified by silica gel chromatography to give 420 mg of 20-(1,3-dioxolan-2-yl)-3β-acetoxypregn-6-ene-1α,5α-diol showing the following properties.