Procedure:  50 mL 1-neck flask, stirbar, septum, N₂ inlet

                  Dissolved 0.825 g of aldehyde I in 20 ml of dry CH₂Cl₂.  Stirred at rt.  Added 2.230 g of II.  After 16 h the solvent was removed from the reaction mixture by rotary evaporation.  The white solid obtained was triturated with 10:90 EtOAc-hexanes.  The solution was decanted and concentrated by rotary evaporation.  The product was isolated by flash chromatography on silica gel using 10:90 EtOAc-hexanes as eluant.  The product was a clear, colorless oil. 

 

¹H NMR (CDCl₃, 400 MHz) d 6.76 (dt, J = 15.8, 2.3 Hz, H3), 6.14 (d, J = 15.8 Hz, H2), 3.75 (s, CO₂CH₃), 2.37 (dt, J = 6.9, 2.3 Hz, H6), 1.60-1.27 (m, CH₂s), 0.89 (t, J = 6.9 Hz, H11). 

 

notes

 

Generally, stabilized (ie. conjugated) ylides such as

 

will react well with aldehydes but give greatly diminished yields on reaction with ketones.  The stabilized ylides also generally yield trans olefins whereas their unstabilized counterparts tend to yield cis olefins.