Normally in schmidt reaction of ketones, amides are formed however for some reason here further reaction takes place and a tetrazole is formed. Here is my try for this reaction mechanism, (if my mechanism attempt is wrong please point out the mistakes and the proper mechanism.)
relating to the mechanisms I have the following doubts:
is this a special case of reaction or are tetrazoles formed with many different ketone reactions? if not, what makes this case special?
what are the driving forces in each step? is the aromaticity the main reason?