Divergent Total Syntheses of Enmein-Type Natural Products: (?)-Enmein, (?)-Isodocarpin, and (?)-Sculponin R
Divergent total syntheses of the enmein-type natural products (?)-enmein, (?)-isodocarpin, and (?)-sculponin R have been achieved in a concise fashion. Key features of the strategy include 1) an efficient early-stage cage formation to control succeeding diastereoselectivity, 2) a one-pot acylation/akylation/lactonization to construct the C-ring and C8 quarternary center, 3) a reductive alkenylation approach to construct the enmain D/E rings and 4) a flexible route to allow divergent syntheses of three natural products.
STRUCTURES OF EFFUSANINS, ANTIBACTERIAL DITERPENOIDS FROM RABDOSIA EFFUSA
Five new diterpenoids, effusanin A, B, C, D and E with antibacterial activity were isolated from the stem and leaves of Rabdosia effusa and their structures were deduced from chemical and spectral findings.