Synthesis of (±)-11-deoxy-15-ethynyl prostaglandins

This article describes the preparation of (±)-11-deoxy-15-ethynyl prostaglandins ( & ). The key step involves a conjugate addition of the substituted 1-lithio-1-oct-1-ene ( ) to the cyclopentenone ( & ) to furnish 11-deoxy-prostaglandin skeleton in a simple fashion. Of particular interest in this synthesis is the preparation of alkyl side chain ( ) which was achieved in an efficient three-step synthesis starting from the readily available β-iodo vinyl ketone ( ).