Diarylmethyl bromides added to asymmetric diarylethylenes to give the corresponding 1,1,3,3‐tetra‐arylprop‐1‐enes 3. Bromination of these propenes, gave 2‐bromoprop‐1‐enes 4 which were readily converted with ethanolic potassium hydroxide to the allenes 5. The structure of the propenes and 2‐bromoprop‐1‐enes was confirmed by ozonolysis.
When 2‐bromo‐2‐methyl‐1, 1‐di‐p‐methoxyphenylethylene was heated to boiling with sodium‐hydroxyethoxide in ethylene glycol, 1,1‐di‐p‐methoxyphenylallene 7 was formed.