Question

Draw the products formed in each reaction sequence.

a.

b.

Short answer

a.

b.

Step-by-step solution

Wittig reaction

A carbon nucleophile is utilized to generate alkenes in a Wittig reaction. The C=O is transformed into C=C in a Wittig reaction.

Limitation and uses of Wittig reaction

Wittig reaction generates a combination of alkene stereoisomers in certain reactions. Several natural products like $\mathit{\beta }$-carotene can be prepared from the Wittig reagent.

Products formed in each reaction sequence

a.The given alkyl halide reacts with PPh₃ leading to the formation of phosphonium salts. The salt undergoes deprotonation with BuLi to form ylide. The final product is obtained by the reaction of Wittig reagent and C₆H₅CH₂CH₂CHO can be given as:

Reaction of compound a

b.The phosphonium salt is generated by the reaction of the given alkyl halide with PPh₃ . The deprotonation of the phosphonium salt with BuLi leads to the generation of a ylide.

The final product formed by the reaction of the ylide with CH₃CH₂CH₂CHO can be given as:

Reaction of compound b