A facile general route to enantiomerically pure 3,4-cis-dialkyl-substituted gamma -lactones and 4,5-cis-dialkyl-substituted delta -lactones by TiCl4-mediated Evans asymmetric aldolization as the key step is exemplified by synthesis of cis-(3R,4R)-3-methyldecan-4-olide and (4R,5R)-aerangis lactone.
Precursor Directed Biosynthesis of an Orthogonally Functional Erythromycin Analogue: Selectivity in the Ribosome Macrolide Binding Pocket
作者:Colin J. B. Harvey、Joseph D. Puglisi、Vijay S. Pande、David E. Cane、Chaitan Khosla
DOI:10.1021/ja304682q
日期:2012.7.25
antibiotic activity on the size and degree of unsaturation of the precursor. Based on these leads, we also report the precursor-directed biosynthesis of 15-propargyl erythromycin A, a novel antibiotic that not only is as potent as erythromycin A with respect to its ability to inhibit bacterial growth and cell-free ribosomal protein biosynthesis but also harbors an orthogonal functional group that is capable
大环内酯类抗生素红霉素 A 及其半合成类似物已成为治疗传染病最有用的抗菌剂之一。使用最近开发的用于 6-脱氧红霉素 D 类似物的前体导向生物合成和菌落生物测定的化学遗传策略,我们确定了一类新的炔基和烯基取代的大环内酯类,其活性与天然产物的活性相当。进一步的分析揭示了抗生素活性对前体的大小和不饱和度的显着和出乎意料的依赖性。基于这些线索,我们还报告了 15-炔丙基红霉素 A 的前体导向生物合成,
Synthesis of Natural Fragrant Molecules <i>cis</i>-3-Methyl-4-decanolide and Aerangis Lactone. General Enantioselective Routes to β,γ-<i>cis</i>-Disubstituted γ-Lactones and γ,δ-<i>cis</i>-Disubstituted δ-Lactones
作者:Yikang Wu、Xin Shen、Chao-Jun Tang、Zhi-Long Chen、Qi Hu、Wei Shi
DOI:10.1021/jo025540o
日期:2002.5.1
(S)-phenylalanine-derived 2-oxazolidinone or thiazolidinethione as chiralauxiliary, whereas the (S,S) ones were constructed with auxiliary prepared from (R)-phenylglycine. NaBH(4)/CaCl(2)/THF in the presence of a small amount of EtOH was introduced as a new effective method for reductive cleavage of chiral oxazolidinone auxiliaries. Previously unknown, tricky concentration effects were observed during the monotosylation