Chapter 7: Q12P-d (page 197)

Rank the substituents in each of the following sets according to the sequence rules:
$- C H_{2} C H_{3}, - C \equiv C H, - C \equiv N, - C H_{2} O C H_{3}$

Short Answer

Expert verified

Higher to lower ranking: $- {CH}_{2} {OCH}_{3} > - C \equiv N > - C \equiv C H > - {CH}_{2} {CH}_{3}$

Step by step solution

E and Z designation

Disubstituted alkenes with two substituents other than hydrogen on the double bond are only named using the cis-trans system. But when trisubstituted and tetra substitution of the double bond is present then the E and Z system is used for describing alkene stereochemistry.

Rule for ranking substituents

Consider each of the double-bond carbons separately and ranks the two substituents according to the atomic number of the first atom in each. An atom with a higher atomic number will rank higher.

If the first atom same then, look at the second, third, or fourth atoms away from the double-bond until the first difference is found.

Multiple-bonded atoms are equivalent to the same number of single-bonded atoms.

Ranking of given groups

As ranking is atomic number dependent, more the atomic number higher will be ranking. So,

In $- {CH}_{2} {OCH}_{3}$ carbon is attached two hydrogens and one oxygen.
In $- C \equiv N$ carbon is attached to three nitrogen.
In carbon $- C \equiv C H$ is attached to three carbon.
In carbon $- {CH}_{2} {CH}_{3}$ is attached to two hydrogens and one carbon.

So, higher to lower-ranking: $- {CH}_{2} {OCH}_{3} > - C \equiv N > - C \equiv C H > - {CH}_{2} {CH}_{3}$

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!

Recommended explanations on Chemistry Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Rank the substituents in each of the following sets according to the sequence rules:
$- C H_{2} C H_{3}, - C \equiv C H, - C \equiv N, - C H_{2} O C H_{3}$

Short Answer

Step by step solution

E and Z designation

Rule for ranking substituents

Ranking of given groups

One App. One Place for Learning.

Most popular questions from this chapter

Recommended explanations on Chemistry Textbooks

Inorganic Chemistry

Physical Chemistry

Ionic and Molecular Compounds

The Earths Atmosphere

Chemical Analysis

Nuclear Chemistry

Study anywhere. Anytime. Across all devices.

Rank the substituents in each of the following sets according to the sequence rules:-CH2CH3,-C≡CH,-C≡N,-CH2OCH3

Short Answer

Step by step solution

E and Z designation

Rule for ranking substituents

Ranking of given groups

One App. One Place for Learning.

Most popular questions from this chapter

Recommended explanations on Chemistry Textbooks

Inorganic Chemistry

Physical Chemistry

Ionic and Molecular Compounds

The Earths Atmosphere

Chemical Analysis

Nuclear Chemistry

Study anywhere. Anytime. Across all devices.

Rank the substituents in each of the following sets according to the sequence rules:
$- C H_{2} C H_{3}, - C \equiv C H, - C \equiv N, - C H_{2} O C H_{3}$