I wonder if anyone has any helpful suggestions. I am trying to prepare triphenylphosphoranylidene crotonaldehyde (a 4-carbon ylid with two conjugated double bonds, one from the alpha carbon to P, and terminating in an aldehyde) from the corresponding bromide Wittig salt (which was prepared from bromocrotonaldehyde, E-double bond). The only literature reference I can find is a Tet. Lett from the early 1980s and all it basically says is that the ylid was liberated from the salt in CH2Cl2 with cold 1M NaOH, then the crude extract was triturated with cold acetone. I have tried this and it will not work. The only solid I can triturate is a brown amorphous powder that has a m.p. 10C higher than the lit value; this isn't the desired product as it doesn't react as expected. I am confident that the starting bromide salt is the correct material (based on m.p.). Anyone have any tips?