The Wittig reaction is useful for placing double bonds in less stable positions. For example, the following transformation is easily accomplished using a Wittig reaction.
(a) Show how you would use a Wittig reaction to do this.
(b) Show how you might do this without using a Wittig reaction, and explain why the Wittig reaction is a much
Here we have to explain the synthesis of the given chemical reaction by wittig reaction and the synthesis of the same chemical reaction by without using wittig method..
The Wittig reaction or Wittig olefination is a chemical reaction of an aldehyde or ketone with a triphenyl phosphonium ylide (often called a Wittig reagent) to give an alkene and triphenylphosphine oxide.
ylide aldehyde or ketone alkene
The nucleophilic C of the ylide Wittig reagent adds to the electrophilic C in the polar carbonyl group, electrons from the C=O π bond are used to form a σ bond to the +ve P atom. This creates a cyclic intermediate called an oxaphosphetane.
Decomposition of the intermediate by breaking the C-P and C-O σ bonds leads to the formation of the C=C π bond of the alkene and triphenylphosphine oxide.