What is the possible mechanism for this reaction? Activated zinc in presence of concentrated hydrochloric acid is used for Clemmensen reduction, that is conversion of ketone group to methylene group.
I'd expect the product to be 1-methyl-2-propyl-pyrrolidine.propylpyrrolidine:
However, ring expansion occurs leading to a piperidine derivative. Could anyone please explain or provide a mechanism for the conversion? Thanks!