English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Divergent total syntheses of (-)-kopsifoline D and (-)-deoxoapodine are detailed from a common pentacyclic intermediate 15, enlisting the late-stage formation of two different key strategic bonds (C21-C3 and C21-O-C6) unique to their hexacyclic ring systems that are complementary to its prior use in the total syntheses of kopsinine (C21-C2 bond formation) and (+)-fendleridine (C21-O-C19 bond formation). The combined efforts represent the total syntheses of members of four classes of natural products from a common intermediate functionalized for late-stage formation of four different key strategic bonds uniquely embedded in each natural product core structure. Key to the first reported total synthesis of a kopsifoline that is detailed herein was the development of a transannular enamide alkylation for late-stage formation of the C21-C3 bond with direct introduction of the reactive indolenine C2 oxidation state from a penultimate C21 functionalized Aspidosperma-like pentacyclic intermediate. Central to the assemblage of the underlying Apidosperma skeleton is a powerful intramolecular [4 + 2]/[3 + 2] cycloaddition cascade of a 1,3,4-oxadiazole that provided the functionalized pentacyclic ring system 15 in a single step in which the C3 methyl ester found in the natural products served as a key 1,3,4-oxadiazole substituent, activating it for participation in the initiating Diels-Alder reaction and stabilizing the intermediate 1,3-dipole.

Total Syntheses of (−)-Kopsifoline D and (−)-Deoxoapodine: Divergent Total Synthesis via Late-Stage Key Strategic Bond Formation