How many substrates will show rearrangement during  $S_{N}1$  reaction?

1. Hydride shift 2. No rearrangement       3. Methyl shift         4. No rearrangement  
5. Methyl shift           6. No rearrangement      7. Ring expansion    8. Ring expansion
9. Hydride shift         10. No rearrangement  
     Number of molecules that undergo rearrangement reaction during  $S_{N}1$  are 6