1214749-97-9Relevant academic research and scientific papers
Total synthesis of kopsinine
Xie, Jian,Wolfe, Amanda L.,Boger, Dale L.
, p. 868 - 870 (2013)
The use of a powerful intramolecular [4 + 2]/[3 + 2] cycloaddition cascade of an 1,3,4-oxadiazole in the divergent total synthesis of kopsinine (1), featuring an additional unique SmI2-promoted transannular cyclization reaction for formation of the bicyclo[2.2.2]octane central to its hexacyclic ring system, is detailed.
Total syntheses of (-)-kopsifoline D and (-)-deoxoapodine: Divergent total synthesis via late-stage key strategic bond formation
Lee, Kiyoun,Boger, Dale L.
, p. 3312 - 3317 (2014/03/21)
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 synthesis of (+)-fendleridine (aspidoalbidine) and (+)-1 -acetylaspidoalbidine
Campbell, Erica L.,Zuhl, Andrea M.,Liu, Christopher M.,Boger, Dale L.
supporting information; experimental part, p. 3009 - 3012 (2010/04/30)
A total synthesis of the Aspidosperma alkaloids (+)-fendleridine and (+)-1-acetylaspidoalbidine is detailed, providing access to both enantiomers of the natural products and establishing their absolute configuration. Central to the synthetic approach is a
