Question

Give common names for the following compounds.

(a)${\mathbf{CH}}_3-\mathbf{C}\equiv \mathbf{C}-{\mathbf{CH}}_2-{\mathbf{CH}}_3$ (b)$\mathbf{Ph}-\mathbf{C}\equiv \mathbf{C}-\mathbf{H}$

(c) 3-methyloct-4-yne (d)${\left({\mathbf{CH}}_3\right)}_3\mathbf{C}-\mathbf{C}\equiv \mathbf{C}-\mathbf{CH}\left({\mathbf{CH}}_3\right){\mathbf{CH}}_2-{\mathbf{CH}}_3$

Short answer

The common name of the following compounds are:

(a) ${\mathrm{CH}}_3-\mathrm{C}\equiv \mathrm{C}-{\mathrm{CH}}_2-{\mathrm{CH}}_3$:Ethylmethylacetylene

(b) role="math" localid="1652877728716" $\mathrm{Ph}-\mathrm{C}\equiv \mathrm{C}-\mathrm{H}$: Phenylacetylene

(c) 3-methyloct-4-yne : Sec-butyl propyl acetylene

(d) ${\left({\mathrm{CH}}_3\right)}_3\mathrm{C}-\mathrm{C}\equiv \mathrm{C}-\mathrm{CH}\left({\mathrm{CH}}_3\right){\mathrm{CH}}_2{\mathrm{CH}}_3$: Sec-butyl-tert-butyl-acetylene

Step-by-step solution

Step-by-Step SolutionStep 1: Common naming

The IUPAC system of nomenclature is provided to name the compound by a standard name by applying the rules and regulations of the nomenclature so that the given compound is identified by the standard common name all over the world.

Step 2: Common name of compounds

(a) As the compound contains a triple bond, to either side of it there is methyl and ethyl group present, the compound is named ethylmethylacetylene.

${\mathrm{CH}}_3-\mathrm{C}\equiv \mathrm{C}-{\mathrm{CH}}_2-{\mathrm{CH}}_3$

Ethylmethylacetylene

(b) Acetylene group corresponds to the presence of a triple bond, to which phenyl group (${\mathrm{C}}_6{\mathrm{H}}_5$) is attached, thus, the name of the compound is phenylacetylene.

$\mathrm{Ph}-\mathrm{C}\equiv \mathrm{C}-\mathrm{H}$

Phenylacetylene

(c) As on either side of the acetylene group propyl group comprising on the carbon and butyl group comprising of four carbon atoms are present, so the name of the compound is sec-butyl propylacetylene.

Sec-butyl propylacetylene

(d) In this compound on either side of the acetylene group tert butyl and sec butyl group are present, so the name of the compound is sec-butyl-tert-butyl-acetylene.

${\left({\mathrm{CH}}_3\right)}_3\mathrm{C}-\mathrm{C}\equiv \mathrm{C}-\mathrm{CH}\left({\mathrm{CH}}_3\right){\mathrm{CH}}_2{\mathrm{CH}}_3$

Sec-butyl-tert-butyl-acetylene