Question

IUPAC name i) (CH3)2 сно сH3
ii) CH2=CH-CH (CH3)2 ​

Answer 1

i.
`(CH_3)_2CHCH_3`

The IUPAC name
`(CH_3)_2CHCH_3` is 2-methylpropane.

ii)
`CH_2=CH-CH(CH_3)_2`

The IUPAC name of
`CH_2=CH-CH(CH_3)_2` is 3-methyl-1-butene.

Here are the steps on how to find the IUPAC names of these compounds:

• Identify the longest carbon chain.
• Number the carbon atoms in the longest chain, starting from the end that is closest to a double bond or triple bond.
• Give the carbon atoms in the longest chain a number, starting from 1 and continuing to the end of the chain.
• If there are any substituents (groups of atoms that are attached to the main chain), identify them and give them a name.
• Write the name of the compound, starting with the name of the longest chain and then adding the names of the substituents.

In the first compound, the longest carbon chain is 3 carbons long. The double bond is on the 2nd carbon atom, so we number the carbon atoms starting from the end that is closest to the double bond. The substituents are two methyl groups, which are attached to the 1st and 3rd carbon atoms. The IUPAC name of the compound is 2-methyl propanal.

In the second compound, the longest carbon chain is 4 carbons long. The double bond is on the 2nd carbon atom, so we number the carbon atoms starting from the end that is closest to the double bond. The only substituent is a methyl group, which is attached to the 3rd carbon atom. The IUPAC name of the compound is 3-methylbut-1-ene.