Lachnanthospirone, a dimeric 9-phenylphenalenone from the seeds of ell.

A Cytotoxic Heterodimeric Cyclic Diarylheptanoid with a Rearranged Benzene Ring from the Seagrass Zostera marina

“…Zosterabisphenone C ( 1 ) is characterized by the rearrangement of one benzene ring to a carboxycyclopentenone, observed here for the first time in a diarylheptanoid. Only two similar, but different, spirolactone systems have been reported so far as natural products, namely, lachnanthospirone ( 6 ) and dendrochrysanene ( 7 ) (Chart ), and both are rearranged products from symmetric aromatic dimers. A total synthesis of dendrochrysanene has been reported from a phenolic precursor, involving FeCl 3 -promoted one-step dimerization and framework rearrangement of the dimer …”

Recent advances in oxidative phenol coupling for the total synthesis of natural products

“…The original isolation paper hypothesized that lachnanthospirone (not shown) could be biosynthetically assembled via an oxidative coupling of a phenol and β-ketoester. 167 To probe the synthetic feasibility, Pappo and co-workers coupled 53a and 53b using their optimized oxidative conditions to afford the lachnanthospirone core 53 in a 43% yield with sequential C–C and C–O bond formation (Scheme 42).…”

Fortschritte der Chemie organischer Naturstoffe / Progress in the Chemistry of Organic Natural Products

“…They vary structurally mainly by their oxygenation pattern and the position of the phenyl ring (Fig. For the unique 'dimeric' spiro compound lachnanthospirone (273) (710), Photo X. Dimeric types like 3,3'-bis-hydroxyanigorufone (272) (709) have only rarely been identified.…”