In the reaction scheme shown below, $\mathrm{Q}, \mathrm{R},$ and $\mathrm{S}$ are the major products.

 The correct structure of 

 

• A

  $\mathrm{S}$ is 
• Correct answer
  B

  $\mathrm{Q}$ is 
• C

  $\mathrm{R}$ is 
• Correct answer
  D

  $\mathrm{S}$ is 

Hence, the correct answer is options: 'B', 'D'.