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.
α,β-unsaturated esters is achieved, involving successively the Sharpless epoxidation of allylicalcohols, oxidation to glycidic acids, conversion into α,β-epoxy diazomethyl ketones, and irradiation in ethanol at 300 nm. Intermediates in the photo-induced rearrangement are epoxy ketenes, which undergo ethanolysis with simultaneous opening of the epoxide, preferably via a transition state involving the