Jun 26, 2018
Preparation of a phosphonium ylide for a Wittig olefination.
Triphenyl phosphonium ylides also called Wittig reagents. They are usually prepared from a phosphonium salt, and a strong base such as sodium hydroxide, potassium tert-butylate (as in this case, added on the second gif) or butyllithium.
What happenes here? This:
[Ph3P+CH2R]X− + C4H9Li → Ph3P=CHR + LiX + C4H10
The ylide (Ph3P=CHR) is often a colored compound. In my case it was deep red, almost black, as seen on the above gifs.