We have to discuss Butyl Lithium reacting with Nitroalkane. In presence of two equivalents of BuLi nitroalkane produced the dianion. Which is react with benzyl halide (e.g- PhCH2Br) formation of Carbon-Carbon signal bond in the alpha position of dianion.
Problem-solve:
The Reagents and reaction mechanism questions-answer for any entrance level exam preparation. Students and Master of chemical science who are practice the question solution series. First of all, try to think of the right approach: solve the question very easy way.
Q.8. The Major product B form Following the reaction: where A is intermediate of this reaction. Predict the product A and B with the proper mechanism.
Answer:
In this case, the use of two equivalents of butyllithium for produced of dianions. The dianions give products in good yield.
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| The answer to Reagent and reaction mechanism question no.8. BuLi with Nitroalkanes |
All reaction mechanisms are the same as discussed in the previous article or questions. The question is almost identical: replaced the carbonyl compound with a nitro-group containing the compound.
Reaction mechanism:
- Butyllithium act as a base which is abstract the most acidic proton in nitroalkanes. the more acidic protons are mentioned in the alpha position of the given nitro compound. and formation of the dianion.
- The dianion (like enolate) acts as a nucleophile and attaches to benzyl halide. That is on type Nucleophilic substitution reaction. Where release the Bromium ions.
- This process goes through strong work up in H3O+.
- Produced the product with a (carbon-carbon signal bond formation) good yield.
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| Answer: Reaction mechanism of question no.8. |
Reference:
Modern organic synthesis by Carruthers Book. Chapter: Carbon-Carbon Singal Bond formation. In part of Organolithium catalysts or reagents react with a carbonyl compound: ketone, ester, aldehyde, etc. Correspond to Nitroalkynes (Nitro group contain compound) react with organolithium reagents (BuLi).
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