Total synthesis of 14-membered ring β-resorcylic acid lactone (+)-monocillin II

This study outlines the total synthesis of (+)-monocillin II, wherein a cis -isomer selectively produces a trans -isomer during the ring-closing metathesis. The Mitsunobu reaction conducted at −60 °C, facilitating the formation of an ester bond, was the key to completing the total synthesis, which was accomplished in the longest linear sequence of 10 steps with an overall yield of 9.3%. The total synthesis of β-resorcylic acid lactone (+)-monocillin II was achieved via the Mitsunobu reaction and other key reactions.