The optimization of mechanochemical conditions reveals that high yields and complete stereoselectivity of synthesis of Z-5a can be achieved under various conditions, including with LiOH or piperidine alone and with the addition of basic Al₂O₃ or TiO₂ as milling auxiliaries. While these milling auxiliaries assist in product recovery, they are chemically active (not just inert physical mediums) and, therefore, cannot be universally applied across different types of reactions.