2671-45-6Relevant academic research and scientific papers
Concise Total Syntheses of (+)-Haplocidine and (+)-Haplocine via Late-Stage Oxidation of (+)-Fendleridine Derivatives
White, Kolby L.,Movassaghi, Mohammad
, p. 11383 - 11389 (2016)
We report the first total syntheses of (+)-haplocidine and its N1-amide congener (+)-haplocine. Our concise synthesis of these alkaloids required the development of a late-stage and highly selective C-H oxidation of complex aspidosperma alkaloid derivatives. A versatile, amide-directed ortho-acetoxylation of indoline amides enabled our implementation of a unified strategy for late-stage diversification of hexacyclic C19-hemiaminal ether structures via oxidation of the corresponding pentacyclic C19-iminium ions. An electrophilic amide activation of a readily available C21-oxygenated lactam, followed by transannular cyclization and in situ trapping of a transiently formed C19-iminium ion, expediently provided access to hexacyclic C19-hemiaminal ether alkaloids (+)-fendleridine, (+)-acetylaspidoalbidine, and (+)-propionylaspidoalbidine. A highly effective enzymatic resolution of a non-β-branched primary alcohol (E = 22) allowed rapid preparation of both enantiomeric forms of a C21-oxygenated precursor for synthesis of these aspidosperma alkaloids. Our synthetic strategy provides succinct access to hexacyclic aspidosperma derivatives, including the antiproliferative alkaloid (+)-haplocidine.
Enantioselective Total Syntheses of (+)-Fendleridine and (+)-Acetylaspidoalbidine
Ghosh, Arun K.,Born, Joshua R.,Kassekert, Luke A.
, p. 5167 - 5175 (2019/05/10)
Enantioselective syntheses of hexacyclic aspidoalbidine alkaloids (+)-fendleridine (2) and (+)-acetylaspidoalbidine (3) are described. These syntheses feature an asymmetric decarboxylative allylation and photocyclization of a highly substituted enaminone. Also, the synthesis highlights the formation of a C19-hemiaminal ether via a reduction/condensation/intramolecular cyclization cascade with the C21-alcohol. The present synthesis provides convenient access to the aspidoalbidine hexacyclic alkaloid family in an efficient manner.
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
