Crown ether catalyzed stereospecific synthesis of Z- and E-stilbenes by Wittig reaction in a solid-liquid two-phases system

Article abstract of DOI:10.1016/0040-4039(96)00802-7

Potassium hydroxide and a catalytic amount of 18-crown-6 are used, in alternative to the classical Wittig conditions, to prepare very rapidly and stereoselectively Z- and E-stilbenes. In particular, the use of benzyltriphenylphosphonium iodides always leads to a complete Z- stereospecificity, while benzyldiphenylchlorophosphonium salts give a complete E-stereospecificity.