Question

The wittig reaction involves coupling between a phosphonium ylide and a carbonyl-containing molecule. if a chemist wants to use the wittig reaction to synthesize 2-methyl-2-pentene, which reactants should be used?

Answer 1

In the Wittig reaction to synthesize 2-methyl-2-pentene, a phosphonium ylide and a carbonyl-containing molecule, such as an aldehyde or a ketone, are needed as reactants.

Step-by-step explanation:

The reactants needed for the Wittig reaction to synthesize 2-methyl-2-pentene are a phosphonium ylide and a carbonyl-containing molecule. In this case, the carbonyl-containing molecule should be an aldehyde or a ketone. The phosphonium ylide is usually generated from a phosphine and an alkyl halide. For example, one possible combination of reactants could be triphenylphosphine and methyl iodide to form the phosphonium ylide, which can then react with an aldehyde or ketone to produce 2-methyl-2-pentene.

Answer 2

George Wittig was awarded the Nobel Prize in Chemistry in 1979. The crown of his work is the discovery of the alkene synthesis from carbonyl compounds and phosphorus ylides. In his honor, this reaction was later called the Wittig reaction.Wittig found that phosphoric ylides attack the carbonyl group in aldehydes and ketones, creating alkenes, as a result of the double bond between ylide and carbonyl carbon.

For a synthesis of 2-methyl-2-pentene over Wittig reaction as phosphonium ylide we will use triphenyl(propylidene)phosphorane and as carbonyl-containing molecule a propan-2-one (reaction is shown in the picture below).