The Total Synthesis of Coleophomones B, C, and D

Members of the coleophomone family of natural products all possess several intriguing and
challenging architectural features, as well as exhibit unusual biological activity. They, therefore, constitute
attractive targets for synthesis. In this Article, we describe the total synthesis of coleophomones B (2), C
(3), and D (4). The highly strained and congested 11-membered macrocycle of coleophomones B (2) and
C (3) was constructed using an impressive olefin metathesis reaction. Furthermore, both of the requisite
geometric isomers of the Δ16,17 within the macrocycle could be accessed from a common precursor,
facilitating a divergence that lent the coleophomone B (2)/C (3) synthesis an unusually high degree of
efficiency. The synthesis of coleophomone D (4) confirmed that it exists as a dynamic mixture of isomeric
forms with a different aromatic substitution pattern from the other family members.