Log out Go to App
Go to App

Learning Materials

Features

Discover

Chapter 21: Problem 4

The following organic compounds cannot exist. Why? a. 2 -chloro-2-butyne b. 2 -methyl-2-propanone c. 1,1 -dimethylbenzene d. 2 -pentanal e. 3 -hexanoic acid f. 5,5 -dibromo- 1 -cyclobutanol

Short Answer

Expert verified
The organic compounds a, b, c, and f cannot exist due to the following reasons: a. 2-chloro-2-butyne: Carbon 2 cannot simultaneously form a bond with a hydrogen atom and a chlorine atom due to the adjacent triple bond. b. 2-methyl-2-propanone: The carbonyl carbon in a ketone should only be connected to two alkyl groups, but it connects to three in this case. c. 1,1-dimethylbenzene: The first carbon is bonded to two methyl groups, leaving no room for it to bond to other carbons within the benzene ring. f. 5,5-dibromo-1-cyclobutanol: The numbering of the substituents is incorrect, and a cyclobutane ring has only four carbons. The correct name should be 1,1-dibromo-3-cyclobutanol.

Step by step solution

01

Understand IUPAC Nomenclature Rules

When naming organic compounds, several rules and guidelines must be followed according to the International Union of Pure and Applied Chemistry (IUPAC). Keep these rules in mind while critically examining each compound.
02

Analyze Compound a (2-chloro-2-butyne)

The name implies the following structure: \(CH_3-CCl-C\equiv C\). Notice that you have a triple bond between carbons 3 and 4. Due to the triple bond between two carbons, carbon 2 can only form one extra bond, but it should have two bonds in this case (one with a hydrogen atom and another with a chlorine atom) which is impossible. Therefore, 2-chloro-2-butyne cannot exist.
03

Analyze Compound b (2-methyl-2-propanone)

The name implies the following structure: \(CH_3-C(COCH_3)CH_3\). The problem here is that the second carbon atom attaches the carbonyl carbon (carbon with a double bond to an oxygen atom) in a ketone along with the methyl group. However, the carbonyl carbon should only be connected to two alkyl groups (i.e., R-C(O)-R'). Therefore, 2-methyl-2-propanone cannot exist.
04

Analyze Compound c (1,1-dimethylbenzene)

The name implies the following structure: \(CH_2(CH_3)_2\) A benzene ring always has a cyclic structure with six carbon atoms connected with alternating single and double bonds. In the given structure, the first carbon is bonded to two methyl groups, leaving no room for it to bond to other carbons within the ring. Therefore, 1,1-dimethylbenzene cannot exist.
05

Analyze Compound d (2-pentanal)

The name implies the following structure: \(CH_3-CH_2-CH_2-CHO\). There is no problem with the structure, and it exists as a real compound. The correct name should be pentanal or pentan-1-al since aldehyde functional groups always occur at the terminal of the carbon chain.
06

Analyze Compound e (3-hexanoic acid)

The name implies the following structure: \(CH_3-CH_2-CH_2-COOH\). As with the previous example, there is no issue with the structure, and the correct name should be hexanoic acid or hexan-1-oic acid since carboxylic acid functional groups always occur at the terminal of the carbon chain.
07

Analyze Compound f (5,5-dibromo-1-cyclobutanol)

The name implies the following structure: \([\stackrel{OH}{\bullet}]\mathrm{C_3B_2}\). The problem here lies in the numbering of the substituents. The dibromo substituents are at position 5, which doesn't exist in a cyclobutane ring, which has only four carbons. Additionally, the numbering of the substituents within the cycloalkane should be 1,1-dibromo-3-cyclobutanol. Therefore, 5,5-dibromo-1-cyclobutanol cannot exist. In summary, understanding the rules of IUPAC nomenclature and chemical structures will help in determining if a given organic compound can exist.

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

If you had a group of hydrocarbons, what structural features would you look at to rank the hydrocarbons in order of increasing boiling point?

Consider the following reactions. For parts \(\mathrm{b}-\mathrm{d},\) see Exer cise 62 a. When \(\mathrm{C}_{5} \mathrm{H}_{12}\) is reacted with \(\mathrm{Cl}_{2}(g)\) in the presence of ultraviolet light, four different monochlorination products form. What is the structure of \(\mathrm{C}_{5} \mathrm{H}_{12}\) in this reaction? b. When \(C_{4} H_{8}\) is reacted with \(H_{2} O\), a tertiary alcohol is produced as the major product. What is the structure of \(\mathrm{C}_{4} \mathrm{H}_{8}\) in this reaction? c. When \(\mathrm{C}_{7} \mathrm{H}_{12}\) is reacted with HCl, 1 -chloro- 1 -methylcyclo hexane is produced as the major product. What are the two possible structures for \(\mathrm{C}_{7} \mathrm{H}_{12}\) in this reaction? d. When a hydrocarbon is reacted with \(\mathrm{H}_{2} \mathrm{O}\) and the major product of this reaction is then oxidized, acetone (2-propanone) is produced. What is the structure of the hydrocarbon in this reaction? e. When \(\mathrm{C}_{5} \mathrm{H}_{12} \mathrm{O}\) is oxidized, a carboxylic acid is produced. What are the possible structures for \(\mathrm{C}_{5} \mathrm{H}_{12} \mathrm{O}\) in this reaction?

Draw the structural formula for each of the following. a. 3 -isobutylhexane b. 2,2,4 -trimethylpentane, also called isooctane. This substance is the reference (100 level) for octane ratings. c. 2 -tert-butylpentane d. The names given in parts a and c are incorrect. Give the correct names for these hydrocarbons.

How would you synthesize each of the following? a. 1,2-dibromopropane from propene b. acetone (2-propanone) from an alcohol c. tert-butyl alcohol ( 2 -methyl-2-propanol) from an alkene (See Exercise 62.) d. propanoic acid from an alcohol

Draw the structural formula for each of the following. a. formaldehyde (methanal) b. 4 -heptanone c. 3 -chlorobutanal d. \(5,5-\) dimethyl- 2 -hexanone
See all solutions

Recommended explanations on Chemistry Textbooks

Inorganic Chemistry

Read Explanation

Organic Chemistry

Read Explanation

Chemical Reactions

Read Explanation

Making Measurements

Read Explanation

The Earths Atmosphere

Read Explanation

Chemistry Branches

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