title: Synthesis, structure and inhibitory activity of a stereoisomer of oseltamivir carboxylate.
abstract: A stereodivergent plan is presented leading to all eight stereoisomers of oseltamivir carboxylate (OC). Key chemical manoeuvers are (1) a three-component vinylogous Mukaiyama-Mannich reaction, which sets the whole carbon skeleton and heteroatom substituents, and (2) an intramolecular, silylative Mukaiyama aldol reaction, which creates the targeted carbocycle. The viability of the plan was demonstrated by the first total synthesis of 4-epi-oseltamivir carboxylate (6), accessed in 15 steps from glyceraldehyde, o-anisidine and pyrrole siloxydiene precursors. Compound 6 inhibits influenza A virus strains H1N1 and H3N2 at the μM level, about 150 000-fold less than the OC reference, testifying that the stereodisposition of the C4 acetamido function is key for enzyme recognition. Guided by in-depth structural evaluation including NMR solution studies, molecular mechanics simulations, docking analyses and X-ray crystallography, rationalization of the biological verdict was established.
authors.affiliation: Dipartimento di Farmacia, Università degli Studi di Parma, Parco Area delle Scienze 27A, I-43124 Parma, Italy. andrea.sartori@unipr.it franca.zanardi@unipr.it.
authors.forename: Andrea
authors.initials: A
authors.lastname: Sartori
authors.forename: Luca
authors.initials: L
authors.lastname: Dell'Amico
authors.forename: Lucia
authors.initials: L
authors.lastname: Battistini
authors.forename: Claudio
authors.initials: C
authors.lastname: Curti
authors.forename: Silvia
authors.initials: S
authors.lastname: Rivara
authors.forename: Daniele
authors.initials: D
authors.lastname: Pala
authors.forename: Philip S
authors.initials: PS
authors.lastname: Kerry
authors.forename: Giorgio
authors.initials: G
authors.lastname: Pelosi
authors.forename: Giovanni
authors.initials: G
authors.lastname: Casiraghi
authors.forename: Gloria
authors.initials: G
authors.lastname: Rassu
authors.forename: Franca
authors.initials: F
authors.lastname: Zanardi
mesh_terms: D000998:Antiviral Agents / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D018360:Crystallography, X-Ray; D004305:Dose-Response Relationship, Drug; D053118:Influenza A Virus, H1N1 Subtype / Q000187:drug effects*; D053122:Influenza A Virus, H3N2 Subtype / Q000187:drug effects*; D008826:Microbial Sensitivity Tests; D008958:Models, Molecular; D015394:Molecular Structure; D053139:Oseltamivir / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology; D013329:Structure-Activity Relationship
chemical_list: D000998:Antiviral Agents; D053139:Oseltamivir; C535162:oseltamivir carboxylate