Question

Name the following:

Short answer

1. IUPAC name: 6-methyl-oct-2-yne.
2. IUPAC name: 5-ethyl-4-methyl-hept-1-yne.
3. IUPAC name: 2-bromo-oct-4-yne.

Step-by-step solution

Rules of IUPAC nomenclature

There are some rules to be followed for the naming of a structure and these are given as follows,

1. Finding the longest chain.
2. Numbering the chain according to the priority order of double bond, triple bond and functional group.
3. Functional group should be written in an alphabetical order means if there is methyl and ethyl group, put ethyl group at 1^st as e comes earlier than m in Alphabets.
4. Among two or more functional group, the name of the compounds will be based on that group which has higher priority.
5. An alkene group will be named as ‘ene’ and alkyne group will be named as ‘yne’.

IUPAC names of the given compounds

The systematic names are given below, using the IUPAC rules.1^st we have levelled the longest chain considering the position of functional group, and then it is written in alphabetical order.

Name of the compounds

The systematic name of the compounds is given below,

IUPAC name: 6-methyl-oct-2-yne.

IUPAC name: 5-ethyl-4-methyl-hept-1-yne.

IUPAC name: 2-bromo-oct-4-yne.