General procedure for Wittig olefination without ylide pre-formation A 7 mL Teflon™ milling vessel equipped with one 12 mm stainless steel ball, was charged with the aldehyde/ketone substrate (0.5 mmol, 1 equiv.), the respective phosphonium halide (0.6 mmol, 1.2 equiv.), and potassium tert-butoxide (0.7 mmol, 1.4 equiv.). The closed Teflon™ vessel was mounted into the holding station of an IST636 mixer mill and milling was conducted at a frequency of 36 Hz for 30 seconds.