β-Keto vinylic sulfones, the key building blocks for the synthesis of the title compounds, were prepared by two different routes. NaBH4 reduction of these compounds afforded β-hydroxy vinylic sulfones which were dehydrated with acetic anhydride and BF3·Et2O to obtain bis(styryl) sulfones. Alternatively, one-pot synthesis of these bis(styryl) sulfones was also achieved directly from β-keto vinylic sulfones by treating with NaBH4 in EtOH followed by refluxing with concentrated HCl.
β-keto vinylic sulfones - β-hydroxy-(E)-vinylic sulfones - (E,E)-bis(styryl) sulfones - styrylsulfinate - Knoevenagel condensation
