Here I don't see ZnCl2 participating in any of the steps. So what does it actually do?
Another mechanism that I found on internet and in the book of David klein is Zncl2 forms a complex compound by forming a bond with oxygen. Then oxygen has a formal positive charge and the leaving group turns into a good one than before. The next steps are simple SN1 reaction. If this is the right one then why H+ ion from HCl doesn't do the job that ZnCl2 is doing like the previous reaction?