The reason behind loss of optical activity of 3-Bromo-3-methylhexane when dissolved in nitromethane should be explained. Concept introduction: Haloalkane solvolysis is a typical example of unimolecuar substitution. It proceeds via two-step mechanism. The first slow step that determines rate is the removal of leaving group from the substrate haloalkane and generates a carbocation. Since the rate is only governed by substrate alone and no other nucleophile or solvent it is termed as unimolecuar substitution. The final step is attack of nucleophile on carbocation generated and formation of racemic products. The most important outcome of unimolecuar substitution is conversion of an optically active substrate to racemic mixture of products. Tertiary or secondary halides undergo fastest unimolecuar substitution as they can readily form the tertiary carbocation followed by secondary and least reactive are primary. The haloalkanes react with various solvents such as water, ethanol to give substituted products that have halide replaced by nucleophilic part of solvent. Such reactions are termed solvolysis. The experimental order of reactive for three types of halides towards solvolysis is as follows: Tertiary > > secondary > primary

Question

Want to see the full answer?

Answer 1

Question

Chapter 7.3, Problem 7.3E

Interpretation Introduction

Interpretation: The reason behind loss of optical activity of 3-Bromo-3-methylhexane when dissolved in nitromethane should be explained.

Concept introduction: Haloalkane solvolysis is a typical example of unimolecuar substitution. It proceeds via two-step mechanism. The first slow step that determines rate is the removal of leaving group from the substrate haloalkane and generates a carbocation. Since the rate is only governed by substrate alone and no other nucleophile or solvent it is termed as unimolecuar substitution. The final step is attack of nucleophile on carbocation generated and formation of racemic products. The most important outcome of unimolecuar substitution is conversion of an optically active substrate to racemic mixture of products.

Tertiary or secondary halides undergo fastest unimolecuar substitution as they can readily form the tertiary carbocation followed by secondary and least reactive are primary.

The haloalkanes react with various solvents such as water, ethanol to give substituted products that have halide replaced by nucleophilic part of solvent. Such reactions are termed solvolysis. The experimental order of reactive for three types of halides towards solvolysis is as follows:

Tertiary>> secondary>primary

Expert Solution & Answer

Want to see the full answer?

Check out a sample textbook solution

See solution

Students have asked these similar questions

(b) Consider the reaction of 1-bromobutane with a large excess of ammonia (NH3). Draw the reactants, the transition state, andthe products. Note that the initial product is the salt of an amine (RNH3+ Br - ), which is deprotonated by the excess ammonia to give the amine.

Synthesize Chloramphenicol from Toluene or Benzaldehyde. Draw and explain step by step please.(p.s: if you can, can you write what the reagents does?) (Drug Chemistry)

4. Synthesis Using the carbon-containing starting material(s), propose a synthesis by drawing structures for all intermediates. The carbon atoms in the product must originate from the starting material(s) (or a carbene/carbenoid or CO₂), but you may use as many equivalents of each starting material as you would like, and any reagent/reaction you know. (note: no mechanisms are required). (a) || محمد b