converted into secondary alkyllithium and secondary alkylcopper compounds with very high retention of configuration. Quenching with various electrophiles, including chiral epoxides, provided a range of chiral molecules with high enantiomericpurity (>90 % ee). This method has been applied in an iterative fashion in the total synthesis of (−)‐lardolure in 13 steps and 5.4 % overall yield (>99 % ee, dr>99:1)
stereoselective total synthesis of jomthonic acid A is described. The key features of the synthetic strategy are a Sharpless asymmetric epoxidation, a Gilmann reagent-induced methylation, a Mitsunobu reaction, a Yamaguchi esterification, and an O-(benzotriazol-1-yl)-N,N,N′,N′-tetramethyluronium tetrafluoroborate (TBTU)-mediated amide coupling. Jomthonic acid A is an architecturally rare amino acid containing
描述了乔松酸 A 的立体选择性全合成。该合成策略的关键特征是 Sharpless 不对称环氧化、吉尔曼试剂诱导的甲基化、光信反应、山口酯化和 O-(苯并三唑-1-基)-N,N,N',N'-四甲基脲四氟硼酸盐 (TBTU) 介导的酰胺偶联。Jomthonic acid A 是一种结构上罕见的氨基酸,包含一个 β-甲基苯丙氨酸残基和一个 4-甲基-(2E,4E)-六-2,4-二烯酸酯部分。当针对小鼠 ST-13 前脂肪细胞进行测试时,它显示出抗糖尿病和抗动脉粥样硬化活性。
Total Syntheses of (+)-Tedanolide and (+)-13-Deoxytedanolide
作者:Joshua R. Dunetz、Lisa D. Julian、Jason S. Newcom、William R. Roush
DOI:10.1021/ja8063205
日期:2008.12.3
13-deoxytedanolide. This led to the decision to pursue the tedanolide synthesis via C(15)-(S)-epimers, since this stereochemical change would destabilize the hemiketal that plagued the attempted synthesis of tedanolide via C(15)-(R) intermediates. However, use of C(15)-(S)-configured intermediates required that the side-chain epoxide be introduced very late in the synthesis, owing to the ease with which
1,3-Asymmetric Induction in Diastereoselective Allylations of Chiral <i>N</i>-Tosyl Imines
作者:Anna Lo、David A. Gutierrez、Garrett Toth-Williams、James C. Fettinger、Jared T. Shaw
DOI:10.1021/acs.joc.1c02691
日期:2022.3.4
Lewis acid mediated allylations of β-alkoxy N-tosyl imines using allyltrimethylsilane lead to 3-alkoxy homoallylic N-tosyl amines with anti-selectivity. Two methods of Cu(OTf)2-mediated allylations are reported herein, demonstrating that diastereoselectivity can be achieved through 1,3 acyclic stereocontrol of β-chiral aldimines. Observed selectivity trends and computational evidence suggest selectivity
Studies on the Synthesis of Tedanolide. 2. Stereoselective Synthesis of a Protected C(1)−C(12) Fragment
作者:William R. Roush、Jason S. Newcom
DOI:10.1021/ol0272343
日期:2002.12.1
[reaction: see text] Highly diastereoselective syntheses of diketo esters 6a and 6b are described. These intermediates undergo efficient aldol reactions with protected C(13)-C(21) aldehydes 3 and 23, thereby providing advanced C(1)-C(21) tedanolide seco ester precursors 9a and 9b.