Further studies on total synthesis of sarain A. efforts toward annulation of the macrocyclic rings

Research was conducted to examine the annulation of the two macrocyclic rings onto the central tricyclic nucleus of sarain A. A ring-closing olefin metathesis method using the Grubbs ruthenium catalyst was employed for the formation of the western macrocyclic ring. As a result, a major intermediate lactam has been developed which will be employed in a total synthesis of the natural product using the the macrocyclization technique.