Synthesis of parazoanthine B and analogs

A versatile synthesis of the natural product parazoanthine B (2) and its analogs, parazoanthine C (3) and 18-deoxy-parazoanthine B (4), has been accomplished by a key coupling reaction between a hydantoinic compound and an ?-bromo-acetophenone derivative. The synthetic approach is designed to address preparation of a wider group of parazoanthine B analogs characterized by the presence of the 5,6-double bond of Z-configuration.