Step 1: Understanding the Concept:
The given molecule is a substituted cycloalkane. The principal parent ring is cyclobutane.
It has two types of substituents attached to the ring: one methoxy group (\( -\text{OCH}_3 \)) and two methyl groups (\( -\text{CH}_3 \)) on the same carbon.
We must apply IUPAC rules to number the ring carbons to give the lowest possible locants to these substituents and then arrange them alphabetically in the name. Step 2: Key Formula or Approach:
1. Identify the parent cyclic alkane.
2. Number the ring starting from one substituent and proceeding towards the others to get the lowest set of locants (Lowest Locant Rule).
3. If two different numbering schemes give the same set of locants, assign the lower number to the substituent cited first alphabetically.
4. Assemble the name, listing substituents alphabetically with their respective locants. Step 3: Detailed Explanation:
The parent ring is cyclobutane (4 carbons).
The substituents are at opposite corners. Let's test the possible numbering schemes.
Scheme A: Start at the carbon bearing the methoxy group as C1.
Counting around the ring, the carbon with the two methyl groups will be C3.
The set of locants is (1, 3, 3) because there are two methyls on carbon 3.
Scheme B: Start at the carbon bearing the two methyl groups as C1.
Counting around the ring, the carbon with the methoxy group will be C3.
The set of locants is (1, 1, 3) because there are two methyls on carbon 1.
Applying the Lowest Locant Rule: Compare the sets term by term.
Set A: 1, 3, 3
Set B: 1, 1, 3
The first point of difference is the second number. Since \( 1<3 \), Scheme B (1, 1, 3) provides the lower set of locants and is therefore the correct numbering.
So, the two methyl groups are at position 1, and the methoxy group is at position 3.
Alphabetical arrangement: The substituents are "methoxy" and "methyl".
Comparing the letters: m-e-t-h-o... vs m-e-t-h-y...
'o' comes before 'y' in the alphabet, so "methoxy" is cited before "methyl".
Constructing the name: 3-methoxy-1,1-dimethylcyclobutane. Step 4: Final Answer:
The correct IUPAC name is 3-Methoxy-1,1-dimethylcyclobutane.
