title: General strategy for the synthesis of B1 and L1 prostanoids: synthesis of phytoprostanes (RS)-9-L1-PhytoP, (R)-9-L1-PhytoP, (RS)-16-B1-PhytoP, and (RS)-16-L1-PhytoP.
abstract: In this paper we describe a novel general synthetic approach to B1- and L1-type phytoprostanes, which are formed in vivo from free-radical-catalyzed nonenzymatic peroxidation of α-linolenic acid (1). The synthesis of phytoprostanes (RS)-9-L1-PhytoP (5), (R)-9-L1-PhytoP (5a), (RS)-16-B1-PhytoP (6), and (RS)-16-L1-PhytoP (7) exemplifies this strategy. The common starting compound 8 has been proved to be synthetically equivalent to a cyclopent-2-en-1-one synthon having opposite donor and acceptor properties at carbons α and β, respectively. Key steps include the chemoselective lithiation of a 1-iodo-2-bromoolefin, the introduction of the side chains by transition-metal catalysis following Heck- or Suzuki-type protocols, the construction of an enone moiety by a mild Au(I)-catalyzed Meyer Schuster rearrangement, and a lipase-mediated hydrolysis of methyl esters to deliver the phytoprostanes as free carboxylic acids.
authors.affiliation: Sezione di Chimica Organica, Dipartimento di Chimica, Università di Pavia , Via Taramelli 12, 27100 Pavia, Italy.
authors.forename: Ruggero
authors.initials: R
authors.lastname: Beretta
authors.forename: Mirko
authors.initials: M
authors.lastname: Giambelli Gallotti
authors.forename: Umberto
authors.initials: U
authors.lastname: Pennè
authors.forename: Alessio
authors.initials: A
authors.lastname: Porta
authors.forename: Juan Fernando
authors.initials: JF
authors.lastname: Gil Romero
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Zanoni
authors.forename: Giovanni
authors.initials: G
authors.lastname: Vidari
mesh_terms: D002264:Carboxylic Acids / Q000737:chemistry*; D002384:Catalysis; D005231:Fatty Acids, Unsaturated / Q000138:chemical synthesis* / Q000737:chemistry*; D005609:Free Radicals / Q000737:chemistry*; D005663:Furans / Q000138:chemical synthesis* / Q000737:chemistry*; D008049:Lipase / Q000737:chemistry*; D011453:Prostaglandins / Q000138:chemical synthesis* / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D002264:Carboxylic Acids; D005231:Fatty Acids, Unsaturated; D005609:Free Radicals; D005663:Furans; D011453:Prostaglandins; C500684:phytoprostane B1 type I; D008049:Lipase