Chapter 22, Problem 27QE

(a)

Interpretation Introduction

Interpretation:

Name has to be determined for the given compound.

Concept Introduction:

A common nomenclature of naming organic compounds has been developed by IUPAC.  By usage of this nomenclature or rules, memorizing of names of organic compounds is not necessary.

IUPAC rules for naming alkanes:

There are about five rules that has to be followed for naming an alkane and they are,

• The longest continuous carbon chain in the compound has to be identified.  This is known as parent compound.  From this the parent name is obtained.  Suffix “–ane” (for alkane) is added at the end of the prefix which gives information about the number of carbon atoms.
• Numbering has to be done so that the lowest number is given to the first group that is encountered in the parent chain.
• Naming and numbering has to be given for each atom or group that is attached to the parent chain.  Numbering has to be done in a way that substituents get the least numbering.
• If the same substitution is present in the parent chain more than once, a separate prefix is added which tells about the number of times the substituent occurs.  Prefixes used are di-, tri-, tetra-, penta- etc.
• Name of the substituents has to be placed in an alphabetical order before the parent compound name.

(b)

Interpretation Introduction

Interpretation:

Name has to be determined for the given compound.

Concept Introduction:

Refer part (a).

(c)

Interpretation Introduction

Interpretation:

Name has to be determined for the given compound.

Concept Introduction:

Refer part (a).

(d)

Interpretation Introduction

Interpretation:

Given compound has to be named.

Concept Introduction:

IUPAC rules for naming cycloalkanes:

A common nomenclature of naming organic compounds has been developed by IUPAC.  By usage of this nomenclature or rules, memorizing of names of organic compounds is not necessary.

• The number of carbon atoms present in the ring is counted and the name of the alkane that has the same number of carbon atoms is given by adding prefix “cyclo-” to the alkane name.
• If the ring is substituted, then the names of the group or atoms have to be placed before the name of cycloalkane.  If only one substituent is present, then number is not required.
• If the ring contains more than one substituent, then the numbers has to be used in a way that it gives the lowest position for the substituents.