Convert the following condensed structures into skeletal structures: CH3CH2CH2CH2CH2CH2OH CH3CH2CH2OCH3 CH3CH2CH(CH3)CH2 CH3CH(NHCH2CH3)CH2CH3 CH3CH(CH3)CH(CH3)CH(CH3)CH2CH2CH3 CH3CH(CH3)CH(CH3)CH(CH3) PROBLEM 18: Convert the structures in Problem 17 into skeletal structures.
The Correct Answer and Explanation is:
Here are the skeletal structures corresponding to the given condensed formulas:
- CH₃CH₂CH₂CH₂CH₂CH₂OH → A straight-chain hexanol with the hydroxyl (-OH) group at the terminal carbon.
- CH₃CH₂CH₂OCH₃ → A straight-chain propoxy-methane (propyl methyl ether).
- CH₃CH₂CH(CH₃)CH₂CH₃ → A straight-chain pentane with a methyl (-CH₃) substituent on the third carbon.
- CH₃CH(NHCH₂CH₃)CH₂CH₃ → A straight-chain butylamine with an ethylamine (-NHCH₂CH₃) group attached to the second carbon.
- CH₃CH(CH₃)CH(CH₃)CH(CH₃)CH₂CH₂CH₃ → A branched octane with three methyl (-CH₃) groups positioned at the second, third, and fourth carbons.
- CH₃CH(CH₃)CH(CH₃)CH(CH₃) → A branched pentane with three methyl (-CH₃) groups at the second, third, and fourth carbons.
Explanation:
In skeletal formulas, carbon atoms and hydrogen atoms bonded to carbon are typically omitted. Instead, only the bonds between carbon atoms and functional groups are explicitly shown. The carbon backbone is drawn as a zigzag pattern where each vertex represents a carbon atom, and the number of bonds follows valency rules.
For example, CH₃CH₂CH₂CH₂CH₂CH₂OH is represented by a zigzag chain with an -OH functional group at the terminal carbon. Similarly, CH₃CH₂CH(CH₃)CH₂CH₃ is a pentane skeleton with a single branching methyl group at the third carbon. Understanding these skeletal formulas simplifies the visualization of molecular structures, reducing redundancy while preserving structural integrity.
This convention helps chemists efficiently interpret complex molecular architectures, making it easier to discern properties such as symmetry, branching, and functional group placement. Skeletal formulas are particularly useful in organic chemistry when analyzing molecular interactions and stereochemistry.
