* All experimental methods are cited from the reference, please refer to the original source for details. We do not guarantee the accuracy of the content in the reference.
As an illustrative example, an oven dried 250 mE flask ischarged under argon atmosphere with triphenylbutylphosphonium bromide (6.0 mmol) and 40 mE anhydrous tetrahydroffiran (THF). The suspension is cooled to 00 C. and potassium tert-butoxide (6.0 mmol) is added to obtain an orangecolor. The reaction is stirred at ambient temperature for 1-2hours, followed by addition of CsA-aldehyde (2.0 mmol,dissolved in 20 mE anhydrous THF). Stirring is continued forhours at room temperature. The reaction is quenched with10 mE sat. NH4C1 and 20 mE ice-water. The layers are sepa‘ rated and the aqueous phase is extracted with EtOAc. Theorganic layers are combined, washed with brine and driedoverNa2SO4. The solvent is removed and the crude product ispurified over silica gel (hexane/acetone 3:1).