Cipadonoid A, a Novel Limonoid with an Unprecedented Skeleton, from Cipadessa cinerasecns.

Cipadonoid A ( 1), a novel limonoid with an unprecedented skeleton, was isolated from the leaves of Cipadessa cinerasecns. Its structure and relative configuration were determined by spectroscopic analysis and computer modeling. 1represents a new type of limonoid, characterized by a rearranged tetrahydropyranyl ring B incorporating usually exocyclic C-30. A possible biosynthetic pathway of 1was also proposed. [ABSTRACT FROM AUTHOR]