Log out Go to App
Go to App

Learning Materials

Features

Discover

Chapter 4: Problem 61

When 3,3-dimethyl-2-butanol is treated with dilute acid, the most stable carbocation formed is (a) 3,3-dimethyl-2-butyl cation (b) 3,3 -dimethyl-1-butyl cation (c) 2,3-dimethyl-2-butyl cation (d) 2-methyl-2-pentyl cation

Short Answer

Expert verified
Answer: The most stable carbocation formed when 3,3-dimethyl-2-butanol is treated with dilute acid is the 3,3-dimethyl-1-butyl cation.

Step by step solution

01

Write the structure of 3,3-dimethyl-2-butanol

First, draw the structure of 3,3-dimethyl-2-butanol. It is an alcohol with the following structure: H3C-C(CH3)2-CH(OH)-CH3
02

Determine the possible carbocations

When 3,3-dimethyl-2-butanol is treated with dilute acid, it forms a carbocation by losing a water molecule. We can eliminate the hydrogen from the alcohol group and draw the possible cations for each option: (a) 3,3-dimethyl-2-butyl cation: H3C-C(CH3)2-CH(+)-CH3 (b) 3,3-dimethyl-1-butyl cation: H3C-C(CH3)2-C(+)-CH2-CH3 (formed through a 1,2-hydride shift) (c) 2,3-dimethyl-2-butyl cation: H3C-CH(C+H2)-C(CH3)2 (d) 2-methyl-2-pentyl cation: H3C-CH(C+H2)-CH2-C(CH3)2
03

Analyze the stability of each carbocation

Evaluate each carbocation based on the number of alkyl groups attached to the positive carbon. The stability order is tert-butyl cation > secondary cation > primary cation because more electron-donating alkyl groups will distribute the positive charge and make the carbocation more stable. (a) 3,3-dimethyl-2-butyl cation: secondary cation, three hyperconjugative structures (b) 3,3 -dimethyl-1-butyl cation: secondary cation, four hyperconjugative structures (c) 2,3-dimethyl-2-butyl cation: primary cation, two hyperconjugative structures (d) 2-methyl-2-pentyl cation: secondary cation, four hyperconjugative structures
04

Choose the most stable carbocation

Based on the number of hyperconjugative structures, the carbocation with the maximum number of hyperconjugative structures will be the most stable. Both options (b) and (d) have four hyperconjugative structures, but option (b) is already formed within the given structure due to the 1,2-hydride shift. Therefore, the most stable carbocation formed when 3,3-dimethyl-2-butanol is treated with dilute acid is: (b) 3,3 -dimethyl-1-butyl cation

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Start your free trial

Over 30 million students worldwide already upgrade their learning with Vaia!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

The major product formed when 2-bromo-3-methyl-1-phenyl butane is treated with alcoholic KOH is

\(\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{Br}+\mathrm{KI} \stackrel{\text { acetone }}{\longrightarrow} \mathrm{C}_{2} \mathrm{H}_{5}-\mathrm{I}+\mathrm{KBr} \quad \rightarrow(\mathrm{I})\) \(\left(\mathrm{CH}_{3}\right)_{3} \mathrm{C}-\mathrm{Br}+\mathrm{KI} \stackrel{\text { acetone }}{\longrightarrow}\left(\mathrm{CH}_{3}\right)_{3} \mathrm{C}-\mathrm{I}+\mathrm{KBr} \quad \rightarrow(\mathrm{II})\) Reaction (II) is much slower than reaction (I) because (a) \(\left(\mathrm{CH}_{3}\right)_{3} \mathrm{CBr}\) is sparingly soluble in acetone. (b) (I) follows \(\mathrm{S}_{\mathrm{N}} 1\) and (II) follows \(\mathrm{S}_{\mathrm{N}} 2\) mechanism. (c) (I) follows \(\mathrm{S}_{\mathrm{N}} 2\) and (II) follows \(\mathrm{S}_{\mathrm{N}} 1\) mechanism. (d) steric hindrance in the case of reaction (II).

Which among the following most readily undergoes \(S_{N} 2\) reaction?

The compound with zero dipole moment is (a) 1,2 -dichlorobenzene (b) 1,3 -dichlorobenzene (c) 1,4 -dichlorobenzene (d) 1,4 -dihydroxybenzene

Reactions of Grignard reagents Organic compounds which contain atleast one carbon-metal bond are called organometallic compounds. Grignard reagents are very reactive organometallic compounds which are of great synthetic utility. They are used for the synthesis of alcohols, aldehydes, ketones, carboxylic acids, etc. They are however decomposed by compounds which have active hydrogen.
See all solutions

Recommended explanations on Chemistry Textbooks

Making Measurements

Read Explanation

Inorganic Chemistry

Read Explanation

Ionic and Molecular Compounds

Read Explanation

Chemical Reactions

Read Explanation

Kinetics

Read Explanation

Nuclear Chemistry

Read Explanation
View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.

Sign-up for free