Question

Retrosynthesis of compound from phenol, 1-pentyne, and t-butanol...?

Question from packet

Hi y'all! I was hoping someone could explain a mechanism for this reaction and perhaps explain what I did wrong.

For my mechanism I did the following:

  1. Combine trifluoromethanesulfonic anhydride (Tf2O) with phenol --> benzene with attached OTf -to make the alcohol a good leaving group
  2. Combine 1-pentyne with 1 equivalent of HBr and peroxides --> 1-bromo-1-pentene -to set it up for Fiedel-Crafts alkylation and make it a double bound like it is in the desired product
  3. Combine products of 1 and 2 --> 1-phenyl-1-pentene -to replace OTf with the O-P directing alkyl chain
  4. Combine t-butanol and HCl --> chlorine replaces OH -to get good leaving group for FC-type reaction
  5. Combine products from 4 and 5 --> Compound A -Fiedel Crafts alkylation again added to P and O positions (mixture but directions didn't say it had to be pure)

Could you please explain what my proposed mechanism would actually result in and what a good mechanism for this synthesis would be? Thanks in advance!