We commenced by testing two solid bases, K2CO3 (1.6 equiv.) and KO t Bu (1.6 equiv.), which are frequently employed in Wittig reactions in solution, for the solvent-free methenylation of I (0.5 mmol) using PPh3MeBr (1.4 equiv.) with a milling time of 45 minutes at 30 Hz (Figure , entry B7 and A1).