A Protecting Group-Free Synthesis of the Antineoplastic Agent Combretastatin A4

The synthesis of combretastatin A4 (CA4) from commercially available inexpensive materials has been achieved via the Wittig reaction followed by irradiation of the ( Z)/( E)-CA4 reaction mixture with sunlight. The method resulted in ( Z)-CA4 in high yield. This method does not require protection of the phenolic hydroxy group. The synthesis is operationally simple and cost-efficient.