反应详情

3 g of p-fluorobenzyl-triphenylphosphonium bromide (preparable from p-fluorobenzyl bromide and triphenylphosphine) are suspended in 50 ml of tert.butyl methyl ether. The suspension is treated at room temperature with 0.75 g of potassium tert.butylate and stirred for 1.5 hours. Subsequently, the mixture is treated dropwise at 0° C. within 5 minutes with a solution of 1.40 g of trans-4-[trans-4-[2-(1,3-dioxolan-2-yl)ethyl]cyclohexyl]cyclohexanecarboxaldehyde in 25 ml of tert.butyl methyl ether and stirred at room temperature for a further 24 hours. Thereafter, the reaction mixture is taken up diethyl ether, washed several times with water, dried over magensium sulfate, filtered and concentrated. Chromatographic purification of the resulting crude product on silica gel with ethyl acetate/petroleum ether (vol. 3:97) gives β-[trans-4-[trans-4-(2-(1,3-dioxolan-2-yl)ethyl)cyclohexyl]cyclohexyl]-4-fluorostyrene.

1. stirringstirred at room temperature for a further 24 hours
2. washwashed several times with water
3. dry with materialdried over magensium sulfate
4. filtrationfiltered
5. concentrationconcentrated
6. customChromatographic purification of the resulting crude product on silica gel with ethyl acetate/petroleum ether (vol. 3:97)