p-Toluenesulfonic acid → HCID 54124038, Verbindung
Reaktionsgleichung
[C:1]1(C)[CH:6]=CC(S(O)(=O)=O)=C[CH:2]=1.[OH:12][C@:13]([CH3:21])([CH2:19][OH:20])[C:14]([O:16][CH2:17][CH3:18])=[O:15]>>[CH3:2][C:1]1([CH3:6])[O:12][C@@:13]([CH3:21])([C:14]([O:16][CH2:17][CH3:18])=[O:15])[CH2:19][O:20]1Komponenten
3
Versuchsvorschrift
500 mg of p-toluenesulfonic acid were added to 10.7 g of ethyl (R)-2,3-dihydroxy-2-methylpropionate, dissolved in 35 ml of dry, freshly distilled 2,2-dimethoxypropane, and the mixture was stirred at room temperature overnight. The excess dimethoxypropane was removed at 45°/12 mmHg and the residue was vigorously stirred for 30 minutes with 5 ml of 1-N sodium bicarbonate. Then, 150 ml of ether were added thereto and the aqueous phase was separated. The ether solution was washed with saturated brine and then dried over sodium sulfate. After evaporation of the solvent, the product was distilled and there were obtained 11.2 g of ethyl (R)-2,2,4-trimethyl-1,3-dioxolan-4-carboxylate in the form of a colorless liquid; boiling point 81°/15 mmHg.