title: Approach toward the total synthesis of griseoviridin: formation of thioethynyl and thiovinyl ether-containing nine-membered lactones through a thioalkynylation-macrolactonization-hydrostannylation sequence.
abstract: Synthesis of the lactone core 17 of 8-epi-griseoviridin is reported. Thioethynyl derivative 11 was easily prepared via an anionic coupling reaction between acetylenic compound 9 and sulfone 10. After desilylation of 11, saponification of the resulting hydroxy ester 12 followed by a Mitsunobu macrolactonization furnished the unusual triple-bond-containing nine-membered lactone 13 in 50% yield for the last two steps (39% after recrystallization). Stannylation under Magriotis conditions led to the pure regio- and stereocontrolled vinyltin 14 (80% yield). After a Sn/I exchange, palladium-catalyzed carbonylation delivered either the ester lactone 16 in 67% yield or the propargyl amide 17 in 65% yield. Synthesis of propargyl amide 17 of the lactone core of 8-epi-griseoviridin was achieved in 11.9% overall yield from commercial L-cystin dimethyl ester (nine steps).
authors.affiliation: Laboratoire de Synthèse Organique Sélective et Chimie Organométallique, CNRS-UCP-ESCOM, FRE 2126, 13 Bd de l'Hautil, 95092 Cergy-Pontoise Cedex, France.
authors.forename: Carine
authors.initials: C
authors.lastname: Kuligowski
authors.forename: Sophie
authors.initials: S
authors.lastname: Bezzenine-Lafollée
authors.forename: Grégory
authors.initials: G
authors.lastname: Chaume
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Mahuteau
authors.forename: Jean-Claude
authors.initials: JC
authors.lastname: Barrière
authors.forename: Eric
authors.initials: E
authors.lastname: Bacqué
authors.forename: Ange
authors.initials: A
authors.lastname: Pancrazi
authors.forename: Janick
authors.initials: J
authors.lastname: Ardisson
mesh_terms: D000900:Anti-Bacterial Agents / Q000138:chemical synthesis*; D002384:Catalysis; D002625:Chemistry, Organic / Q000379:methods; D002855:Chromatography, Thin Layer; D007783:Lactones / Q000138:chemical synthesis* / Q000737:chemistry*; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D010455:Peptides; D013457:Sulfur Compounds / Q000138:chemical synthesis / Q000737:chemistry; D017971:Tin Compounds / Q000737:chemistry; D014753:Vinyl Compounds / Q000138:chemical synthesis / Q000737:chemistry
chemical_list: D000900:Anti-Bacterial Agents; D007783:Lactones; D010455:Peptides; D013457:Sulfur Compounds; D017971:Tin Compounds; D014753:Vinyl Compounds; C010583:griseoviridin