反应详情

A solution of 4.9 g of 8-[4-(3,4-difluorophenyl)-3-cyclohexenyl]-1.4-dioxaspiro[4.5]decane in 670 ml of ethanol was hydrogenated with 1.0 g Raney nickel at 50° C. under normal pressure until the hydrogen uptake came to a standstill. The reaction mixture was filtered and the filtrate was concentrated. Threefold recrystallization of the obtained crude product (5.0 g) from diethyl ether/hexane yielded 2.52 g of 8-[trans-4-(3,4-difluorophenyl)cyclohexyl]-1, 4-dioxaspiro[4.5]decane. The mother liquors were evaporated. Isomerization of the residue (2.2 g) under inert gas with 11 ml of dimethyl sulfoxide and 0.344 g of potassium tert. butylate at 100° C. for 7 hours yielded after twofold recrystallization further 0.7 g of 8-[trans-4-(3,4-difluorophenyl)cyclohexyl]-1,4-dioxaspiro-[4.5]-decane.

1. filtrationThe reaction mixture was filtered
2. concentrationthe filtrate was concentrated
3. customThreefold recrystallization of the
4. customobtained crude product (5.0 g) from diethyl ether/hexane