title: Efficient construction of the kedarcidin chromophore ansamacrolide.
abstract: [Structure: see text] The streamlined assembly of the ansamacrolide framework of the kedarcidin chromophore via an efficient atropselective Sonogashira coupling step is described. To this end, two newly improved practical syntheses of the cyclopentene and diyne fragments have been developed, which feature 0.2 mol % catalytic loadings for an RCM step and i-PrMgCl/CH2I2 as a new entry to gem-disubstituted epoxides from ketones, both being applicable to 49-g scales.
authors.affiliation: Department of Chemistry, Graduate School of Science, Tohoku University, COE, Sendai 980-8578, Japan.
authors.forename: Yasuhito
authors.initials: Y
authors.lastname: Koyama
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Lear
authors.forename: Fumihiko
authors.initials: F
authors.lastname: Yoshimura
authors.forename: Isao
authors.initials: I
authors.lastname: Ohashi
authors.forename: Tomoko
authors.initials: T
authors.lastname: Mashimo
authors.forename: Masahiro
authors.initials: M
authors.lastname: Hirama
mesh_terms: D000475:Alkenes / Q000138:chemical synthesis / Q000737:chemistry; D000480:Alkynes / Q000138:chemical synthesis* / Q000737:chemistry; D003500:Cyclization; D003516:Cycloparaffins / Q000138:chemical synthesis* / Q000737:chemistry; D053281:Enediynes; D047029:Lactams, Macrocyclic / Q000138:chemical synthesis* / Q000737:chemistry; D018942:Macrolides / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D009281:Naphthalenes / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D000475:Alkenes; D000480:Alkynes; D003516:Cycloparaffins; D053281:Enediynes; D047029:Lactams, Macrocyclic; D018942:Macrolides; D009281:Naphthalenes; C080542:kedarcidin chromophore