The first total synthesis of tanzawaic acid A(GS-1302-3) is described. The stereocontrolled synthetic route allowes the absolute stereochemistry to be determined. One key transformation in the sequence involves a Stille coupling with a highly hindered aryl triflate. Examples and results of several coupling reactions are also included.
Total Synthesis of the Oxopolyene Macrolide (−)-Marinisporolide C
作者:Luiz C. Dias、Emílio C. de Lucca
DOI:10.1021/acs.orglett.5b03352
日期:2015.12.18
The first totalsynthesis of (−)-marinisporolide C was performed in 25 steps (longest linear sequence) and an overall yield of 1%. Due to the high degree of convergence and robustness, the C9–C35 fragment that corresponds to the polyol portion was obtained in gram quantity. Highlights of this synthesis include five highly stereoselective aldol reactions responsible for the construction of five C–C
The first total synthesis of (−)-marinisporolide C is described, which establishes unequivocally the relative and absolute configuration of this oxopolyene macrolide. Key features of this synthesis include a series of highly stereoselective aldol reactions followed by directed reductions to build the polyol domain, a Stille cross-coupling reaction to assemble the polyene, and an intramolecular Hor
Byproduct formation during the biosynthesis of spinosyn A and evidence for an enzymatic interplay to prevent its formation
作者:Byung-sun Jeon、Teng-Yi Huang、Mark W. Ruszczycky、Sei-hyun Choi、Namho Kim、Joseph Livy Franklin、Shang-Cheng Hung、Hung-wen Liu
DOI:10.1016/j.tet.2021.132569
日期:2022.1
Biosynthesis of spinosyn A in Saccharopolyspora spinosa involves a 1,4-dehydration followed by an intramolecular [4 + 2]-cycloaddition catalyzed by SpnM and SpnF, respectively. The cycloaddition also takes place in the absence of SpnF leading to questions regarding its mechanism of catalysis and biosynthetic role. Substrate analogs were prepared with an unactivated dienophile or an acyclic structure
Synthesis of C11-to-C14 methyl-shifted all-<i>trans</i>-retinal analogues and their activities on human aldo-keto reductases
作者:Aurea Rivas、Raquel Pequerul、Vito Barracco、Marta Domínguez、Susana López、Rafael Jiménez、Xavier Parés、Rosana Alvarez、Jaume Farrés、Angel R. de Lera
DOI:10.1039/d0ob01084g
日期:——
The synthesis of these retinoids was based on the formation of a C10–C11 single bond of the pentaene skeleton starting from a trienyl iodide and the corresponding dienylstannanes and dienylsilanes, using the Stille–Kosugi–Migita and Hiyama–Denmark cross-coupling reactions, respectively. Since these reagents differ by the location and presence of methyl groups at the dienylorganometallic fragment, the