Synthesis and Antifungal Activity of Rhodopeptin Analogues. 2. Modification of the West Amino Acid Moiety
摘要:
[GRAPHICS]Structure-activity relationships of the west amino acid modified analogues of rhodopeptins, novel antifungal tetrapeptide isolated from Rhodococcus species Mer-N1033, have been investigated, Among the analogues synthesized, 2,2-difluoro and 2-hydroxy derivatives retained the antifungal activity with better physical properties, i.e., solubility or acute toxicity.
A Lewis base promoted deprotonative pronucleophile addition to silyl acetals has been developed and applied to the iridium-catalyzed reductive Horner–Wadsworth–Emmons (HWE) olefination of esters and the chemoselective reduction of the resulting enoates. Lewis base activation of silyl acetals generates putative pentacoordinate silicate acetals, which fragment into aldehydes, silanes, and alkoxides in
Stereoselective synthesis of fluoroalkenes via (Z)-2-fluoroalkenyliodonium salts
作者:Masanori Yoshida、Ayumu Komata、Shoji Hara
DOI:10.1016/j.tet.2006.05.085
日期:2006.9
Stereoselective synthesis of fluoroalkenes is described. (Z)-2-Fluoro-1-alkenyl(phenyl)iodonium tetrafluoroborates (1) were synthesized stereoselectively in good yields by Michael-type addition of HF to 1-alkynyl(phenyl)iodonium tetrafluoroborates (2) with a commercially available HF reagent, hydrofluoric acid or Et3N-3HF. Pd-catalyzed cross-coupling reactions using 1 gave (Z)-2-fluoro-l-alkene derivatives in moderate yields. The treatment of 1 with KI in the presence of a catalytic amount of CuI gave (Z)-2-fluoro-1-iodo-1-alkenes (3). Pd-catalyzed cross-coupling reactions of 3 gave better results than that of 1, and a variety of (Z)-2-fluoro-l-alkene derivatives were synthesized in good yields. (c) 2006 Elsevier Ltd. All rights reserved.
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作者:Derek C. Martyn、Deborah A. Hoult、Andrew D. Abell
DOI:10.1071/ch01093
日期:——
A systematic study on the Horner-Wadsworth-Emmons (HWE) reaction has shown that ethyl diphenylphosphonoacetate and methyl diphenylphosphonoacetate give a high excess of (Z)-alkenes. These reaction conditions were then used to prepare (Z)-ethyl-5-phenylpent-2-enoate, the corresponding (E)-isomer being prepared by standard Wittig chemistry. Reduction of each allylic ester, with diisobutylaluminium hydride (DIBAL), gave the allylic alcohols (15) and (19), respectively. Epoxidation of (15) and (19), under Sharpless conditions, gave separate samples of all four stereoisomers of 2,3-epoxy-5-phenylpentan-1-ol. Esterification of each isomer with Cbz-valine, under Mitsunobu conditions, provided (9)-(12) which were assayed against HIV protease. The cis series (9)-(10) proved to be significantly more potent than the trans (11)-(12) and, within each of these series, the isomers derived from L-diisopropyltartrate [(9) and (11)] were the most active.
[EN] POLYHYDROXY GLYCOPEPTIDE DERIVATIVES<br/>[FR] DERIVES POLYHYDROXY DE GLYCOPEPTIDES
申请人:ADVANCED MEDECINE INC
公开号:WO2001098329A1
公开(公告)日:2001-12-27
Disclosed are polyhydroxy derivatives of glycopeptides and pharmaceutical compositions containing such glycopeptide derivatives. The disclosed glycopeptide derivatives are useful as antibacterial agents.
Synthesis and Antifungal Activity of Rhodopeptin Analogues. 2. Modification of the West Amino Acid Moiety
作者:Kiyoshi Nakayama、Haruko C. Kawato、Hiroaki Inagaki、Ryohei Nakajima、Akihiro Kitamura、Kazuhiko Someya、Toshiharu Ohta
DOI:10.1021/ol005630k
日期:2000.4.1
[GRAPHICS]Structure-activity relationships of the west amino acid modified analogues of rhodopeptins, novel antifungal tetrapeptide isolated from Rhodococcus species Mer-N1033, have been investigated, Among the analogues synthesized, 2,2-difluoro and 2-hydroxy derivatives retained the antifungal activity with better physical properties, i.e., solubility or acute toxicity.