Question

What is IUPAC name of following compound?

• A. 1-Methoxy-3,3-dimethylcyclobutane
• B. 3-Methoxy-1,1-dimethylcyclobutane
• C. 3,3-Dimethylcyclobutoxymethane
• D. 1-Methoxy-3-isopropylbutane

Hint:

Number the ring to give the substituents the lowest possible locant numbers. Substituents are listed alphabetically.

Answer 1

The Correct Option is D

Concept:
To name a substituted cycloalkane:

• Choose the ring as parent chain.
• Number the ring to give substituents the lowest set of locants.
• Write substituents in alphabetical order.
• Use prefixes such as di-, tri- for repeated groups.

Step 1: Identify parent ring
The given compound contains a four-membered ring: \[ \boxed{\text{Cyclobutane \] So parent name is: \[ \text{cyclobutane} \]
Step 2: Identify substituents
The substituents present are:

• One methoxy group $\left(-OCH_3\right)$
• Two methyl groups $\left(-CH_3\right)$ attached to same carbon

Thus we have: \[ \text{methoxy and dimethyl} \]
Step 3: Number the ring
Start numbering from the carbon carrying two methyl groups to obtain lowest locants. Then numbering gives:

• Carbon-1 : two methyl groups
• Carbon-3 : one methoxy group

So locants are: \[ 1,1 \text{ and } 3 \] This is lower than alternative numbering.
Step 4: Arrange substituents alphabetically
Alphabetical order: \[ \text{methoxy before methyl} \] (While prefix di- is ignored in alphabetizing.) Hence write: \[ 3\text{-methoxy-}1,1\text{-dimethyl} \]
Step 5: Final Answer
The IUPAC name of the compound is: \[ \boxed{3\text{-Methoxy-}1,1\text{-dimethylcyclobutane \] Quick Tip:
For alphabetizing, prefixes like di-, tri-, tetra- are ignored.