title: Total syntheses of (-)- and (+)-boronolide and their plant growth-inhibitory activity.
abstract: Optically pure (+)- and (-)-boronolides were stereoselectively synthesized from yeast reductive products which had been obtained by yeast reduction of one common racemic substrate. The lactone structure of boronolide was constructed by Baeyer-Villiger oxidation. The stereochemistry of the yeast reduction products was studied to obtain the stereocenters at 5 positions of the dodecanolides of (+)- and (-)-boronolides. The stereochemistry of the 6 and 7 positions was obtained by AD-mix-α or β oxidation. The chiral center at the 8 position was constructed by employing (R)-(+)- or (S)-(-)-2-methyl-CBS-oxazaborolidine reduction or the Mitsunobu reaction. The plant growth-inhibitory activity against Echinochloa crusgalli L. of naturally occurring (+)-boronolide was higher than that of the (-)-boronolide.
authors.affiliation: Faculty of Agriculture, Ehime University, 3-5-7 Tarumi, Matsuyama, Ehime 790-8566, Japan. syamauch@agr.ehime-u.ac.jp
authors.forename: Satoshi
authors.initials: S
authors.lastname: Yamauchi
authors.forename: Yasuyoshi
authors.initials: Y
authors.lastname: Isozaki
authors.forename: Hiroki
authors.initials: H
authors.lastname: Nishimura
authors.forename: Tomoko
authors.initials: T
authors.lastname: Tsuda
authors.forename: Hisashi
authors.initials: H
authors.lastname: Nishiwaki
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Shuto
mesh_terms: D001372:Aza Compounds / Q000737:chemistry; D055162:Biocatalysis; D031747:Echinochloa / Q000187:drug effects* / Q000254:growth & development; D007783:Lactones / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology; D015394:Molecular Structure; D010084:Oxidation-Reduction; D010937:Plant Growth Regulators; D011753:Pyrones / Q000494:pharmacology; D013237:Stereoisomerism; D015003:Yeasts / Q000378:metabolism
chemical_list: D001372:Aza Compounds; D007783:Lactones; D010937:Plant Growth Regulators; D011753:Pyrones; C469612:boronolide