Question

Here X and Y respectively are

• A.
  
  
• B.
• C.
• D.

Answer 1

The correct option is B

In the acid-catalysed ring opening of an unsymmetrical epoxide, the nucleophile attacks primarily at the more substituted carbon atom because such carbon of the protonated epoxide has a considerable positive charge.
This resembles like a more stable $2^{\circ }and{3}^{\circ }$ carboncation and hence the reaction is $S_{N}1$ like,

In case of $C{H}_{3}ONa.OC{H}_3$, being a strong nucleophile, opens the strained epoxide ring in a direct $S_{N}2$ reaction, i.e., by attacking at the lest hindered carbon atom,