反应详情

Dissolve 2-ethyl-2-(6-m-methoxyphenyl-6-methyl-3-oxohexyl)-1,3-cyclopentanedione (39.7 g) in benzene (500 ml) and reflux with p-toluenesulfonic acid in water (11.0 g). Remove 2 moles of water, add ethyleneglycol (50 ml) and reflux the solution overnight (16 hours). After working up by the usual procedure, filter repeatedly through Florex in hexane. Recrystallize from ethanol to obtain dl-13β-ethyl-3-methoxy-6-methyl-17,17-ethylenedioxygona-1,3,5-(10),8,14-pentaene (16.8 g), m.p. 120°-122°; ultraviolet absorption peak at 312 mμ, no infrared absorption in the ketone region.

1. temperaturereflux the solution overnight (16 hours)
2. filtrationfilter repeatedly through Florex in hexane
3. customRecrystallize from ethanol