title: Recent methods for the synthesis of (E)-alkene units in macrocyclic natural products.
abstract: (E)-Alkene units are frequently found in macrocyclic natural products. Among the reactions that form the double bond during the cyclization, the classical Horner-Emmons coupling is still frequently used with success. During the last decade, ring-closing metathesis has emerged as a very powerful tool for the synthesis of large rings, but the E/Z selectivity, which is rarely predictable, depends on many factors which will be discussed in this review. The best solution might be a two-step procedure involving ring-closing alkyne metathesis (RCAM) followed by stereoselective reduction of the macrocyclic alkyne unit to the corresponding E double bond.
authors.affiliation: Laboratoire de Synthèse Organique, UMR CNRS 7652, Ecole Polytechnique, DCSO, 91128 Palaiseau Cedex, France. joelle.Prunet@polytechnique.fr
authors.forename: Joëlle
authors.initials: J
authors.lastname: Prunet
mesh_terms: D000475:Alkenes / Q000138:chemical synthesis*; D001688:Biological Products / Q000138:chemical synthesis*; D002384:Catalysis; D003500:Cyclization; D007783:Lactones / Q000138:chemical synthesis*; D012997:Solvents; D013237:Stereoisomerism; D013696:Temperature
chemical_list: D000475:Alkenes; D001688:Biological Products; D007783:Lactones; D012997:Solvents; C049726:patulolide B; C049725:patulolide A