Question

Aldehydes and ketones are converted into alkenes by means of a direct nucleophilic addition called the Wittig reaction.

Answer 1

Answer:

The given statement- Aldehydes and ketones are converted into alkenes by means of a direct nucleophilic addition called the Wittig reaction, is True.

Explanation:

The Wittig reaction converts aldehydes and ketones into alkenes through a simple nucleophilic addition. A triphenylphosphorine ylide, also known as a phosphorane, reacts with an aldehyde/ketone to produce an oxaphosphetane, a four-membered cyclic intermediate. Instead of being isolated, the oxaphosphetane decomposes spontaneously to release triphenylphosphine oxide and an alkene.

In an SN2 reaction, triphenylphosphine, a good nucleophile, reacts with a primary alkyl halide, followed by deprotonation of the carbon with a solid base, such as butyllithium, to form the ylide. In the product alkene, the carbonyl carbon and the carbon initially bound to the halogen become two carbons with a double bond.

The Wittig reaction's true worth lies in its ability to produce an alkene with a predictable structure, as the C=C bond forms exactly where the C=O bond did in the reactant, with no isomers (other than E/Z isomers) forming.

Hence , the correct option is (A) True.