反应详情

To a stirred mixture of 4-methoxy-4-methylpentanal (60 g, 0.46 mol) and ethyl acetoacetate (156 g, 1.2 mol) at 5° C. was added a 21% solution of piperidine in ethanol (4.1 mL). Further additions (4×18 mL) of the piperidine solution were made at about 24 hour intervals. The mixture was heated at reflux for 7 hours and concentrated to about 200 mL volume. Methanol (420 mL), water (420 mL) and sodium hydroxide (24 g) were added and the resulting mixture was heated at reflux 16 hours. Workup gave 3-(3-methoxy-3-methylbut-1-yl)-5-methylcyclohex-5-en-1-one bp0.1 135°-140° C. (69.2 g); NMR(CDCl3)δ1.2(s,6H), 0.9-1.6(m,5H), 1.9(s,3H), 5.9(brs,1H); IR(neat) 2975, 2930, 1675, 1640, 1380, 1080 cm-1 ; MS(m/e) 43, 73, 81, 109, 122, 163, 196.

1. temperatureThe mixture was heated
2. temperatureat reflux for 7 hours
3. concentrationconcentrated to about 200 mL volume
4. additionMethanol (420 mL), water (420 mL) and sodium hydroxide (24 g) were added
5. temperaturethe resulting mixture was heated
6. temperatureat reflux 16 hours