Skip to content

Wittig Reaction

April 22, 2013

Wittig reaction is one of the important method for the synthesis of alkenes. It uses a carbonyl compound as an electrophile, which is attacked by a “phosphorus ylide” called wittig reagent. This reaction is named after a German chemist Georg Wittig in 1954. This reaction is a nucleophilic addition followed by elimination.

The reaction between aldehyde or ketone with triphenyl phosphonium ylide produces alkene and triphenylphosphine oxide.

Wittig reaction

Specific reaction

Wittig reaction example

Mechanism of the reaction

  • The nucleophile attackes the carbon atom and the electrons from the C=O ∏-bond are used to form a σ-bond to the +ve P atom.
  • This creates a cyclic intermeiate called an oxaphosphetane.
  • Intermediate formed undergo decomposition by breaking of C-P bond and C-O σ-bonds leads to the formation of C=C ∏-bond of the alkene and triphenyl phosphine oxide.

Wittig reaction mechanism

Advertisements

From → Uncategorized

Leave a Comment

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: