[OH:1][C:2]1[C:3]([CH3:18])=[C:4]2[C:9](=[C:10]([CH3:13])[C:11]=1[CH3:12])[O:8][C:7]([C:15]([OH:17])=[O:16])([CH3:14])[CH2:6][CH2:5]2.[C:19](OC(=O)C)(=[O:21])[CH3:20]>N1C=CC=CC=1>[C:19]([O:1][C:2]1[C:3]([CH3:18])=[C:4]2[C:9](=[C:10]([CH3:13])[C:11]=1[CH3:12])[O:8][C:7]([C:15]([OH:17])=[O:16])([CH3:14])[CH2:6][CH2:5]2)(=[O:21])[CH3:20]Dissolve 50 grams (0.2 mol) of (6-hydroxy-2,5,7,8-tetramethylchroman-2-yl)carboxylic acid in 150 cm3 of anhydrous pyridine. Add dropwise 9.4 cm3 (0.1 mol) of acetic anhydride under a stream of nitrogen. Stir for 2 hours at a temperature of 30° C. After cooling, pour the mixture onto some ice, extract the resulting product with diethyl ether, and wash the organic phase with a 0.2N hydrochloric acid solution, and then with water until neutral. After evaporation of the solvent, an oily mass is collected which crystallises after trituration in diisopropyl ether.
불러오는 중…