Unlike alcohols which are very unreactive owing to the inability of the hydroxyl to break away on its own, alkyl bromides are very active because the halides are generally good leaving groups. Halides, therefore, are very useful in synthesis because they can be converted to other functional groups. The problem, however, is the difficulty in controlling their behaviors because they react in various pathways, such as SN1, SN2, El and E2. SN2 mechanism occurs when the leaving group is beaking away as the nucleophile attacks the alpha C. This mechanism, therefore, requires that the nucleophile attacks the alpha carbon at the backside because frontside attack inhibits the interaction of the nucleophile and the alpha C because of steric hindrance due to the bulky halide leaving group. This backside attack also results into configuration inversion of the product. SN1, on the other, is not limited to backside attack because by the time the nucleophile attacks, the leaving group is already gone. The problem, however, with SN1 is the possible proliferation of multiple products due to carbocation rearrangement. lide reacte clen SN1 roact

Organic Chemistry
9th Edition
ISBN:9781305080485
Author:John E. McMurry
Publisher:John E. McMurry
Chapter15: Benzene And Aromaticity
Section15.SE: Something Extra
Problem 31AP
icon
Related questions
icon
Concept explainers
Question
100%

Can somone help? It says I got 3 of the 20 blanks incorrect. 

dimethyl sulfoxide
Unlike alcohols which are very unreactive owing to the inability of the hydroxyl to break away on
hydroxyl
its own, alkyl bromides are very active because the halides are generally good leaving groups.
Halides, therefore, are very useful in synthesis because they can be converted to other
aprotic
functional groups . The problem, however, is the difficulty in controlling their behaviors because
they react in various pathways, such as SN1, SN2, E1 and E2.
accelerate
steric hindrance
polar
SN2 mechanism occurs when the leaving group is beaking away as the nucleophile attacks the
alpha C. This mechanism, therefore, requires that the nucleophile attacks the alpha carbon at the
backside because frontside attack inhibits the interaction of the nucleophile and the alpha C because
Rate = k[RX]|nucleophile]
primary
of steric hindrance due to the bulky halide leaving group. This backside attack also results into
t - Buo
configuration inversion of the product. SNI, on the other, is not limited to backside attack because
strong base
by the time the nucleophile attacks, the leaving group is already gone. The problem, however,
with SN1 is the possible proliferation of multiple products due to carbocation rearrangement.
weak base
leaving group
Therefore, a tertiary alkyl halide reacts with a nucleophile via SN1, while a primary reacts via
alpha carbon
SN2.
E2
SN2 reaction rates also vary with the strength of the nucleophile. This idea is validated by the
good
experimental rate equation for SN2 which shows that Rate = k[RX][nucleophile] . Therefore, a
functional groups
primary alkyl halide needs a nucleophile , but a strong base . If the nucleophile is a strong
strong nucleophile
base as well, such as t - Buo . primary alkyl halides undergo elimination instead via E2
carbocation
The solvent affects the SN2 rate as well. Solvents in SN2 reactions of alkyl halides are general
inversion
strong base , but aprotic . Protic solvents turn bases into poor nucleophile. Therefore, protic
Rate = k[RX)
solvents , such as alcohols and water slow down SN2 reactions. However, dimethyl sulfoxide
nucleophile
is a very good solvents for SN2 reactions.
slow down
tertiary
Transcribed Image Text:dimethyl sulfoxide Unlike alcohols which are very unreactive owing to the inability of the hydroxyl to break away on hydroxyl its own, alkyl bromides are very active because the halides are generally good leaving groups. Halides, therefore, are very useful in synthesis because they can be converted to other aprotic functional groups . The problem, however, is the difficulty in controlling their behaviors because they react in various pathways, such as SN1, SN2, E1 and E2. accelerate steric hindrance polar SN2 mechanism occurs when the leaving group is beaking away as the nucleophile attacks the alpha C. This mechanism, therefore, requires that the nucleophile attacks the alpha carbon at the backside because frontside attack inhibits the interaction of the nucleophile and the alpha C because Rate = k[RX]|nucleophile] primary of steric hindrance due to the bulky halide leaving group. This backside attack also results into t - Buo configuration inversion of the product. SNI, on the other, is not limited to backside attack because strong base by the time the nucleophile attacks, the leaving group is already gone. The problem, however, with SN1 is the possible proliferation of multiple products due to carbocation rearrangement. weak base leaving group Therefore, a tertiary alkyl halide reacts with a nucleophile via SN1, while a primary reacts via alpha carbon SN2. E2 SN2 reaction rates also vary with the strength of the nucleophile. This idea is validated by the good experimental rate equation for SN2 which shows that Rate = k[RX][nucleophile] . Therefore, a functional groups primary alkyl halide needs a nucleophile , but a strong base . If the nucleophile is a strong strong nucleophile base as well, such as t - Buo . primary alkyl halides undergo elimination instead via E2 carbocation The solvent affects the SN2 rate as well. Solvents in SN2 reactions of alkyl halides are general inversion strong base , but aprotic . Protic solvents turn bases into poor nucleophile. Therefore, protic Rate = k[RX) solvents , such as alcohols and water slow down SN2 reactions. However, dimethyl sulfoxide nucleophile is a very good solvents for SN2 reactions. slow down tertiary
Expert Solution
steps

Step by step

Solved in 2 steps

Blurred answer
Knowledge Booster
Ethers
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, chemistry and related others by exploring similar questions and additional content below.
Similar questions
  • SEE MORE QUESTIONS
Recommended textbooks for you
Organic Chemistry
Organic Chemistry
Chemistry
ISBN:
9781305080485
Author:
John E. McMurry
Publisher:
Cengage Learning