[alansary]

Hi all,

just comes across this question and i really don't know how to start solving it.

In question A , Do I need to replace the (iPr)3 by (CH3)3 ?
also, the mentioned peaks , are they related to the Me groups ? or to the Hs attached to the ring?

if anyone can give me any tips/hints helping me start solving the problem question A or B , that will be appreciated.

thanks

[Doc Oc]

You're not replacing anything, you're adding a trimethylsilyl group.  That's going to look like a tert-butyl, but with Si as the quaternary center instead of carbon.  You need to figure out where to put that group that makes sense with the NMR spectrum.