Chapter 24, Problem 24.59QP

a)

Interpretation Introduction

Interpretation:

The structure of the alkane cyclopentane has to be predicted.

Concept introduction:

IUPAC Nomenclature of cycloalkanes:

• The longest continuous ring of carbon atoms is identified. The prefix is added with ‘cyclo’.
• The substituent groups attached to the parent chain is identified. A substituent group contains group of atoms attached to the carbon atom of the chain.
• While numbering the longest chain, the substituent should get least possible number.
• Write the name of the compound; the parent name written as last part of the name. The name of the substituents is written as prefix and a hyphen separates the number that the substituents attached with carbon. More than one substituent should be written in alphabetical order.

Explanation of Solution

Given name:  cyclopentane

Predict the longest continuous chain of carbon atoms:

The parent name is CYCLOPENTANE represent the continuous ring of carbon atoms contains five carbons. The Suffix ‘ane’ represents the structure contains only single bonds.

Predict substituents and its location:

No prefix available before the parent name pentane, thus, the structure has no substituents located at any carbon atoms.

Therefore, the structure is

b)

Interpretation Introduction

Interpretation:

The structure of cis-2-butene has to be predicted.

Concept introduction:

IUPAC Nomenclature of alkenes:

• The longest continuous chain of carbon atoms is identified.
• The substituent groups attached to the parent chain is identified. A substituent group contains group of atoms attached to the carbon atom of the chain.
• While numbering the longest chain, the substituent should get least possible number.
• Write the name of the compound; the parent name written as last part of the name. The name of the substituents is written as prefix and a hyphen separates the number that the substituents attached with carbon. More than one substituent should be written in alphabetical order.

Geometric isomers of Alkenes:

Cis-isomer: When two particular atoms (identical group of atoms) are adjacent (on same side) to each other, the alkene is known as cis-isomer.

Trans-isomer: When two particular atoms (identical group of atoms) are opposite from each other, the alkene is known as trans-isomer.

Explanation of Solution

Given name: cis-2-butene

Predict the longest continuous chain of carbon atoms:

The parent name is BUTENE represent the longest chain of carbon atoms contains four carbons. The Suffix ‘ene’ represents presence of double bond at C-2.

Predict substituents and its location:

No prefix available before the parent name pentane, thus, the structure has no substituents located at any carbon atoms. The term ‘cis-’ indicates two hydrogen atoms are located adjacent to each other on same side.

Therefore, the structure is

c)

Interpretation Introduction

Interpretation:

The structure of 2-hexanol has to be predicted.

Concept introduction:

IUPAC Nomenclature of alkanes:

• The longest continuous chain of carbon atoms is identified.
• The substituent groups attached to the parent chain is identified. A substituent group contains group of atoms attached to the carbon atom of the chain.
• While numbering the longest chain, the substituent should get least possible number.
• Write the name of the compound; the parent name written as last part of the name. The name of the substituents is written as prefix and a hyphen separates the number that the substituents attached with carbon. More than one substituent should be written in alphabetical order.

Explanation of Solution

Given name:  2-hexanol

Predict the longest continuous chain of carbon atoms:

The parent name is HEXANOL represent the longest chain of carbon atoms contains six carbons. The Suffix ‘ol’ represents presence of hydroxy group –OH at C-2.

Predict substituents and its location:

The prefix ‘2-‘represent the presence of hydroxy group at C-2.

Therefore, the structure is

d)

Interpretation Introduction

Interpretation:

The structure of 1,4-dibromobenzene has to be predicted.

Concept introduction:

IUPAC Nomenclature of Aromatic compounds:

• The parent compound of aromatic compound is Benzene.
• The substituent groups attached to the parent is identified. A substituent group contains group of atoms attached to the carbon atom of the aromatic ring.
• While numbering the parent, the location of the second group relative to the first substituent uses prefixes like o-ortho (1,2-), m-meta (1,3-), and p-para (1,4) in disubstituted aromatic ring.

Explanation of Solution

Given name: 1,4-dibromobenzene

Predict the parent structure:

The parent name is BENZENE represent the continuous ring of carbon atoms contains six carbons with alternative double bonds.

Predict substituents and its location:

The prefix ‘1, 4-dibromo’ indicates the presence of two identical bromine atom located at C-1 and C-4.

Therefore, the structure is

e)

Interpretation Introduction

Interpretation:

The structure of 2-butyne has to be predicted.

Concept introduction:

IUPAC Nomenclature of alkynes:

• The longest continuous chain of carbon atoms is identified. The suffix is added replaced with ‘yne’.
• The substituent groups attached to the parent chain is identified. A substituent group contains group of atoms attached to the carbon atom of the chain.
• While numbering the longest chain, the substituent should get least possible number.
• Write the name of the compound; the parent name written as last part of the name. The name of the substituents is written as prefix and a hyphen separates the number that the substituents attached with carbon. More than one substituent should be written in alphabetical order.

Explanation of Solution

Given name: 2-butyne

Predict the longest continuous chain of carbon atoms:

The parent name is BUTYNE represent the longest chain of carbon atoms contains four carbons. The Suffix ‘yne’ represents the structure contains only one triple bonds at C-2.

Predict substituents and its location:

No prefix available before the parent name pentane, thus, the structure has no substituents located at any carbon atoms.

Therefore, the structure is