Question

The compound $R$ is:

• A.
  
• B.
  
• C.
  
• D.
  

Answer 1

Aldol condensation of isobutyraldehyde $\left(P\right)$ with formaldehdye $\left(Q\right)$ gives 3-hydroxy-2,2-dimethylpropanal $\left(R\right)$.

Addition of a molecule of $HCN$ to aldehyde group gives cyanohydrin 2,4-dihydroxy-3,3-dimethylbutanenitrile $\left(S\right)$.

Acidification results in formation of 3-hydroxy-4,4-dimethyldihydrofuran-2 ($3H$)-one.

Option A is correct.