title: Determination of the absolute structure of (+)-cystothiazole B.
abstract: Palladium-catalyzed cyclization-methoxycarbonylation of (2R,3S)-3-methylpenta-4-yne-1,2-diol (6) derived from (2R,3S)-epoxy butanoate 5, followed by methylation, gave the tetrahydro-2-furylidene acetate (-)-7, which was converted to the left-half aldehyde (+)-3. A Wittig reaction between (+)-3 and the phosphoranylide derived from the bithiazole-type phosphonium iodide 4 using lithium bis(trimethylsilyl)amide afforded (+)-cystothiazole B (2), the spectral data of which were identical to those of the natural product (+)-2. Thus the stereochemistry of cystothiazole B (2) was confirmed to be [4R, 5S, 6(E)].
authors.affiliation: School of Pharmaceutical Sciences, Toho University, 2-2-1 Miyama, Funabashi, Chiba 274-8510, Japan.
authors.forename: Takamitsu
authors.initials: T
authors.lastname: Sasaki
authors.forename: Keisuke
authors.initials: K
authors.lastname: Kato
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Akita
mesh_terms: D015394:Molecular Structure; D013844:Thiazoles / Q000737:chemistry*
chemical_list: D013844:Thiazoles; C112183:cystothiazole B