A witting reaction is a type of chemical reaction that involves the conversion of a carbonyl group (such as an aldehyde or ketone) into an alkene through the use of a phosphorus ylide.
Step by step reaction mechanism of a witting reaction:
1. Formation of the ylide: The ylide is formed by the reaction of a phosphonium salt and a strong base. The base deprotonates the phosphonium salt to form the phosphorus ylide, which is a nucleophilic species.
2. Wittig reaction: The ylide attacks the carbonyl carbon of the aldehyde or ketone, forming a new carbon-carbon bond. This results in the formation of an alkene and a phosphine oxide as byproduct.
Overall reaction:
R2C=O + Ph3P=CH2 → R2C=CH2 + Ph3P=O
In this reaction, R represents a substituent on the carbonyl group. The witting reaction is a powerful synthetic tool for the formation of carbon-carbon double bonds and is widely used in organic synthesis.
Define witting reaction,.
Draw a step by step reaction mechanism of each witting reaction
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