Question

What is the IUPAC name of the product Y formed in the given sequence of reactions? \[ \text{Isobutane} \xrightarrow{\text{KMnO}_4} \text{X} \xrightarrow{\text{(i) Na, (ii) }\text{CH}_3-\text{Br}} \text{Y} \]

• A. 1, 1, 1-Trimethyl methoxy methane
• B. Methyl, t-Butyl ether
• C. 2-Methyl-2-methoxy propane
• D. 2-Methoxy-2-methyl propane

Hint:

While "methyl tert-butyl ether" (MTBE) is the common name of Y, the question explicitly asks for the IUPAC name.
Always ensure you choose the systematic IUPAC name (2-methoxy-2-methylpropane) rather than the common name.

Answer 1

The Correct Option is D

Step 1: Oxidise isobutane's one tertiary C-H bond.
$\text{KMnO}_4$ selectively converts that bond into a C-OH bond, giving tert-butyl alcohol as X, $(\text{CH}_3)_3\text{C-OH}$.
Step 2: Form the alkoxide.
Treating X with sodium metal deprotonates the -OH, giving sodium tert-butoxide.
Step 3: Run the Williamson ether synthesis.
This alkoxide then displaces bromide from methyl bromide, linking a methyl group onto the tert-butyl oxygen and forming the ether $(\text{CH}_3)_3\text{C-O-CH}_3$ as Y.
Step 4: Name the product properly.
Choosing propane as the parent chain with a methoxy substituent at C2 (which also carries the two methyl branches) gives the IUPAC name.
Final answer: Option 4, 2-Methoxy-2-methylpropane.