With the given structures below, give the systematic (IUPAC) name for each of the following compounds:
The Correct Answer and Explanation is :
To systematically name the compounds, we’ll analyze each structure for the longest continuous carbon chain, the substituents, and their positions. Here’s the breakdown of the given structures:
1. Structure: CH₂=CH-CH₂-CH=CH₂
- Longest chain: A 5-carbon chain with two double bonds.
- Numbering: Number from the end closest to the first double bond to give the lowest locants for the double bonds.
- IUPAC Name: 1,4-pentadiene.
2. Structure: CH₂CH(CH₂)₂
- Longest chain: A 4-carbon chain.
- Substituent: A methyl group on the second carbon.
- Numbering: Number from the end closer to the substituent.
- IUPAC Name: 2-methylbutane.
3. Structure: CH₂=CH-CH₂-CH₂-CH=CH-CH₂
- Longest chain: A 7-carbon chain with two double bonds.
- Numbering: Number from the end closest to the first double bond.
- IUPAC Name: 1,5-heptadiene.
4. Structure: CH₂=C(CH₃)-CH₂
- Longest chain: A 3-carbon chain.
- Substituent: A methyl group attached to the second carbon.
- IUPAC Name: 2-methylpropene.
5. Structure: CH₃-CH₂-CH(CH₃)-CH(CH₂CH₃)-CH₂CH₃
- Longest chain: A 6-carbon chain.
- Substituents: A methyl and an ethyl group attached to carbons 3 and 4.
- Numbering: Number from the end closer to the substituents for the lowest locants.
- IUPAC Name: 3-ethyl-4-methylhexane.
Explanation:
Each compound is named following IUPAC nomenclature rules:
- Identify the longest continuous carbon chain (parent chain).
- Identify and name substituents (branches).
- Assign numbers to the chain to give substituents the lowest possible locants.
- List substituents in alphabetical order, separated by commas.
- Indicate the presence of double/triple bonds with suffixes like -ene or -yne, including their positions.
Correct application of these rules ensures systematic naming, avoiding ambiguity in chemical communication.