Synthesis of (+)-fragolide and (−)-pereniporin B via vinylsilane terminated cationic cyclization
摘要:
Enantioselective syntheses of (+)-fragolide and (-)-pereniporin B are detailed. Marino's lactone annulation method was employed to establish relative and absolute stereochemistry at carbon in the bicyclization substrate. Regio- and stereoselective oxidations of tricyclic drimane precursors are described.
Abstract Three new drimane-typesesquiterpenoids, 7α-chloro-6β-hydroxyconfertifoline, 6β,7α-dihydroxyconfertifoline and 6β,7β-epoxyconfertifoline were isolated from the liverwortMakinoacrispata together with the previously known eudesmane-type sesquiterpene lactone, crispatanolide and a sacculatane-type diterpene dialdehyde, perrottetianal A. The stereostructures of the new compounds were established