[CH3:1][C:2]1[N:7]=[C:6]([CH3:8])[C:5]([CH:9]=[CH:10][C:11](=[O:13])[CH3:12])=[C:4]([CH3:14])[N:3]=1.[C:15](OCC)(=O)[CH2:16][C:17]([O:19]CC)=O.[Na].[OH-].[K+].[C:29](=O)(O)[O-].[K+].[CH2:34]([OH:36])[CH3:35]>>[OH:36][C:34]1[CH2:35][CH:9]([C:5]2[C:6]([CH3:8])=[N:7][C:2]([CH3:1])=[N:3][C:4]=2[CH3:14])[CH2:10][C:11](=[O:13])[C:12]=1[C:17](=[O:19])[CH2:16][CH2:15][CH3:29]and (iii) 1-(2,4,6-Trimethylpyrimidin-5-yl)but-1-en-3-one (1.5 g) and sodium diethyl malonate (2.5 equiv) were heated at reflux in absolute ethanol (40 ml) for 13 hr. A dilute aqueous potassium hydroxide solution (4 equiv) was added and the mixture was heated allowing the ethanol to distill off over 4 hr. The hot solution was made just acid by slow addition of a dilute hydrochloric acid solution. Potassium bicarbonate (2equiv) was added and the solvent was evaporated by reduced pressure distillation. The solid residue was thoroughly dried (100° C.; 0.1 mmHg). The residue was extracted with hot anhydrous dimethylformamide (40 ml). The soluble fraction was heated at 100° C. under nitrogen with butyric anhydride (3 ml) for 2 hr. The dimethylformamide (40 ml) was evaporated by reduced pressure distillation and the residue was shaken with a little dilute acetic acid. The whole mixture was extracted into ethyl acetate. The dried (MgSO4) solvent was evaporated and the residue was purified by column chromatography over silica gel with ethyl acetate elution to give 3-hydroxy-5-(2,4,6-trimethylpyrimidin-5-yl)-2-butyrylcyclohex-2-en-1-one as an oil. Pmr spectrum (CDCl3 ; δ in ppm): 1.01 (3H, t); 1.69 (2H, m); 2.3-3.9 (7H, m); 2.57 (6H, s); 2.63 (3H, s); 18.33 (1H, s).
読み込み中…
