62396-80-9Relevant academic research and scientific papers
A transition metal-catalyzed enyne metathesis for the preparation of pyrrolizidine alkaloid core: Application towards the total synthesis of stemaphylline
Kumar, Praveen,Rahman, Md. Ataur,Haque, Ashanul,Singh Yadav, Jhillu
, (2021/03/03)
In this paper, we disclose an efficient route for the synthesis of pyrrolizidine alkaloid core and its application towards the total synthesis of stemaphylline. The key pyrrolizidine core was achieved with Ru-carbene catalyzed ring closing enyne metathesis (RCEM). The effect of different types and amounts of Ru-carbene catalysts, solvents and temperature were systematically studied. The advantage of this method includes the construction of pyrrolizidine alkaloid core in a single operation.
Method for highly selective synthesis of multi-chiral central tetrahydrofuran ring
-
Paragraph 0069-0077, (2019/10/17)
The invention relates to the technical field of organic synthesis, in particular to a method for highly selective synthesis of a multi-chiral central tetrahydrofuran ring. The method has mild conditions, simple reaction steps, easy operation, high regioselectivity and high stereoselectivity. The method comprises the following steps: (a) using L-glutamic acid 1 as a starting material, and carryingout diazotization and ring-closing to obtain a lactone intermediate 2; (b) reducing the carboxyl group in the lactone intermediate 2 to obtain an intermediate 3; (c) protecting the hydroxyl group in the intermediate 3 by TBS to obtain an intermediate 4; (d) carrying out a substitution reaction of the intermediate 4 to obtain an intermediate 5; (e) reducing the intermediate 5 to obtain a precursorcompound of an intermediate 6; (f) carrying out a Wittig reaction of the precursor compound of the intermediate 6 to obtain the intermediate 6; (g) carrying out a Mitsunobu reaction of the intermediate 6 to obtain an intermediate 7; and (h) performing protective group removal and ring-closing on the intermediate 7 under the action of a base to obtain a target product 8.
Multi-Gram Scale Synthesis of Chiral 3-Methyl-2,5-trans-tetrahydrofurans
Qin, Shuanglin,Cao, Yuting,Luo, Yunhao,Jiang, Shende,Clark, J. Stephen,Wang, Xiaoji,Yang, Guang
, (2019/07/12)
In this article, we report the rapid and facile synthesis of chiral 3-methyl-2,5-trans-tetrahydrofurans. This reaction utilizes cheap and easily available starting materials. A domino hydrolysis and intramolecular Michael-type ring closure reaction was the key step. As a result, synthesis of the desired 3-methyl-2,5-trans-tetrahydrofurans could be achieved in gram-scale over seven linear steps with high chemical yield and high diastereoselectivity.
Design and Synthesis of New Acid Cleavable Linkers for DNA Sequencing by Synthesis
Jiang, Min,Tang, Daonian,Zhao, Xiaodong,Li, Qing,Zhuang, Yuan,Wei, Xiaofei,Li, Xiaowei,Liu, Yazhi,Wu, Xin-Yan,Shao, Zhifeng,Gong, Bing,Shen, Yu-Mei
, p. 774 - 785 (2015/10/19)
A new kind of acid sensitive tetrahydrofuranyl (THF) linker was synthesized and then reacted with 5-(6)-carboxytetramethylrhodaminesuccinimidyl ester (5(6)-TAMRA, SE), followed by di(N-succinimidyl) carbonate (DSC) and modified 2′-deoxyuridine triphosphate (dUTP); the final product, as a reversible terminator for DNA sequencing by synthesis (DNA SBS), was given obtained and confirmed by 1H-NMR, 31P-NMR, and HRMS with purity of up to 99%. The synthesized dye-labeled terminator incorporated into DNA strand successfully, and the fluorophore was cleaved completely under acidic conditions. The preliminary results encourage us to explore more acid-sensitive linkers for DNA SBS to increase the cleavage efficiency under weakly acidic conditions.
Practical synthesis of C1-8 fragment of autolytimycin via a chelation-controlled diastereoselective addition of diisopropenylzinc to α-methoxy aldehyde
Yang, Fan,Feng, Liang,Wang, Nengzhong,Liu, Xuge,Li, Jun,Shen, Yuehai
, p. 9463 - 9468 (2013/10/08)
The C1-8 fragment of autolytimycin was synthesized via a reliable 10-step route capable of delivering 41% overall yield at multi-gram scale. As a key step, a chelation-controlled isopropenylation of α-oxygenated aldehydes was established with a reagent combination of diisopropenylzinc, magnesium halide, and a dichloromethane/toluene mixed solvent. Cram-chelate isopropenylation products dominated for aldehydes with a small α-substituents, such as -OMe and -OBn groups, while the Felkin product could be obtained with a bulky -OTBS group.
Synthesis of reblastatin, autolytimycin, and non-benzoquinone analogues: Potent inhibitors of heat shock protein 90
Wrona, Iwona E.,Gozman, Alexander,Taldone, Tony,Chiosis, Gabriela,Panek, James S.
experimental part, p. 2820 - 2835 (2010/08/05)
A full account of an asymmetric synthesis of reblastatin (1) and the first total synthesis of autolytimycin (2) and related structural compounds is described. The syntheses expand the utility of a highly regio- and diastereoselective hydrometalation aldehyde addition sequence to assemble the fully functionalized ansa chain of the natural products. Also documented is an intramolecular copper-mediated amidation reaction to close the 19-membered macrolactams. The amidation reaction was also employed for the generation of structural derivatives (6-9) of phenolic ansamycins. Ansamycin natural products and selected structural analogues were evaluated in a competitive binding assay to breast cancer cell lysate and a cytotoxicity assay. Both reblastatin (1) and autolytimycin (2) were shown to bind the heat shock protein 90 with enhanced binding activity (～25 nM) than 17-allylamino-17-demethoxygeldanamycin (17-AAG, 4), a geldanamycin (3) derivative currently under evaluation for treatment of cancer (～100 nM).
Stereoselective synthesis of the densely functionalized C1-C9 fragment of amphidinolides C and F
Mohapatra, Debendra K.,Dasari, Pavankumar,Rahaman, Hasibur,Pal, Rita
scheme or table, p. 6276 - 6279 (2010/01/18)
The synthesis of the C1-C9 subunit of amphidinolides C and F is described. Key steps include tandem Sharpless asymmetric dihydroxylation-SN2 cyclization reaction, Lewis acid-mediated epoxide opening, Wittig reaction, and Wacker oxidation.
A radical mediated approach to the stereoselective formal total synthesis of (+)-Sch 642305
Chakraborty, Tushar Kanti,Samanta, Rajarshi,Kumar, Pulukuri Kiran
experimental part, p. 6925 - 6931 (2009/12/09)
A formal total synthesis of (+)-Sch-642305 is described. The synthesis, which commenced from a simple chiral synthon (5S)-5-(hydroxymethyl)dihydrofuran-2(3H)-one, employed, as a key step, a radical mediated opening of a chiral epoxy alcohol intermediate with Cp2Ti(III)Cl following an efficient method developed by us earlier. The resultant intermediate radical was intramolecularly trapped by the electron deficient double bond present in the molecule to give rise to its highly functionalized six-membered carbocyclic ring in stereoselective manner.
A synthetic approach to the fusicoccane A-B ring fragment based on a Pauson-Khand cycloaddition/Norrish type 1 fragmentation
Dake, Gregory R.,Fenster, Erik E.,Patrick, Brian O.
, p. 6711 - 6715 (2008/12/22)
(Chemical Equation Presented) A synthetic approach to the A-B ring system within the fusicoccane family of diterpenes is presented. Key steps in this approach are a diastereoselective Pauson-Khand reaction, a Norrish 1 photofragmentation, a Charette cyclopropanation, and a ring-closing metathesis process.
