569-26-6Relevant academic research and scientific papers
Biomimetic Total Syntheses of Ergot Alkaloids via Decarboxylative Giese Coupling
Ge, Yuhua,Wang, Hang,Wang, Hua-Nan,Yu, Shu-Sheng,Yang, Rui,Chen, Xingyue,Zhao, Qin,Chen, Gang
, p. 370 - 375 (2021/01/13)
Biomimetic total syntheses of Festuclavine and Pyroclavine were achieved by a sequential radical coupling. The key steps include intramolecular decarboxylative Giese reaction to form the central C ring and 4-nitrobenzenesulfonyl (Ns)-directed indole C4-H olefination to introduce the indole C4 component. In addition, D-ring formation was completed by decarboxylative alkenylation and intramolecular SN2 reaction.
Asymmetric synthesis method for ergot alkaloids
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Paragraph 0060; 0103; 0104, (2019/02/10)
The invention discloses an asymmetric synthesis method for ergot alkaloids, which belongs to the technical field of chemical synthesis. According to the method, after a cheap and easily available compound 1 and compound 2 are subjected to alkylation, a cy
Biomimetic Total Syntheses of Clavine Alkaloids
Chaudhuri, Saikat,Bhunia, Subhajit,Roy, Avishek,Das, Mrinal K.,Bisai, Alakesh
, p. 288 - 291 (2018/01/17)
Biomimetic total syntheses of either enantiomers of a number of ergot alkaloids, chanoclavine I (1b), chanoclavine I aldehyde (1c), pyroclavine (1e), festuclavine (1f), pibocin A (1g), 9-deacetoxyfumigaclavine C (1h), and fumigaclavine G (1i), have been achieved from seco-agroclavine (1a). The advanced intermediate for seco-agroclavine (1a) was synthesized via a key thiourea-catalyzed intramolecular nitronate addition onto α,β-unsaturated ester.
Total Syntheses of Festuclavine, Pyroclavine, Costaclavine, epi-Costaclavine, Pibocin A, 9-Deacetoxyfumigaclavine C, Fumigaclavine G, and Dihydrosetoclavine
Liu, Haichao,Zhang, Xiwu,Shan, Dong,Pitchakuntla, Mallesham,Ma, Yongfan,Jia, Yanxing
supporting information, p. 3323 - 3326 (2017/06/23)
A new approach for the divergent total synthesis of eight ergot alkaloids is reported. The approach allows the first total syntheses of pyroclavine, pibocin A, 9-deacetoxyfumigaclavine C, and fumigaclavine G and also enables the efficient synthesis of festuclavine, costaclavine, epi-costaclavine, and dihydrosetoclavine. The main feature of the synthesis is the use of an unprecedented Pd-catalyzed intramolecular Larock indole annulation/Tsuji-Trost allylation cascade to assemble the tetracyclic core in one step.
Controlling a structural branch point in ergot alkaloid biosynthesis
Cheng, Johnathan Z.,Coyle, Christine M.,Panaccione, Daniel G.,O'Connor, Sarah E.
supporting information; experimental part, p. 12835 - 12837 (2010/11/05)
The ergot alkaloids are a diverse class of fungal-derived indole alkaloid natural products with potent pharmacological activities. The biosynthetic intermediate chanoclavine-I aldehyde 1 represents a branch point in ergot biosynthesis. Ergot alkaloids festuclavine 2 and agroclavine 3 derive from alternate enzymatic pathways originating from the common biosynthetic precursor chanoclavine-I aldehyde 1. Here we show that while the Old Yellow Enzyme homologue EasA from the ergot biosynthetic gene cluster of Aspergillus fumigatus acts on chanoclavine-I aldehyde 1 to yield festuclavine 2, EasA from Neotyphodium lolii, in contrast, produces agroclavine 3. Mutational analysis suggests a mechanistic rationale for the switch in activity that controls this critical branch point of ergot alkaloid biosynthesis.
Using the Pummerer cyclization-deprotonation-cycloaddition cascade of imidosulfoxides for alkaloid synthesis
Padwa, Albert,Heidelbaugh, Todd M.,Kuethe, Jeffrey T.
, p. 2368 - 2378 (2007/10/03)
The Pummerer reaction of imidosulfoxides bearing tethered alkenyl groups has been employed for the synthesis of several alkaloids. The required imidosulfoxides necessary for the cascade sequence were easily obtained by heating the appropriate amide with (ethylsulfenyl)acetyl chloride followed by sodium periodate oxidation. The initially formed thionium ion, obtained by treating the imidosulfoxide with acetic anhydride and p-toluenesulfonic acid, reacts with the neighboring imido group, and the resulting oxonium ion undergoes subsequent deprotenation to produce an isomunchnone dipole. This mesoionic betaine intermediate undergoes ready intramolecular dipolar cycloaddition across the neighboring π-bond. Exposure of the resulting cycloadducts to additional acetic anhydride leads to ring opening and formation of a 5-acetoxy-substituted 2(1H)-pyridone. This six-ring heterocyclic system constitutes a valuable building block for the synthesis of a variety of pyridine, quinolizidine, and clavine alkaloids. The cyclization-deprotonation-cycloaddition cascade has been successfully applied to the synthesis of the naturally occurring alkaloids onychnine, dielsiquinone, (±)-lupinine, (±)-anagyrine, (±)-pumiliotoxin C, and (±)- costaclavine.
Total synthesis of optically active costaclavine (synthetic studies of indoles and related compounds part 48.)
Osanai, Kumi,Yokoyama, Yuusaku,Kondo, Kazuhiro,Murakami, Yasuoki
, p. 1587 - 1590 (2007/10/03)
The first total synthesis of optically active costaclavine (18), an ergot alkaloid, was accomplished starting from methyl [4R-(Z)]-[4-[[(1,1- dimethylethoxy)carbonyl]methylamino]-3,4-dihydro-1-[(4- methylphenyl)sulfonyl]benz[cd]indol-5(1H)-ylidene]acetate
Synthesis and Dopamine Antagonist Activity of 2-Thioether Derivatives of the Ergoline Ring System
Tupper, David E.,Pullar, Ian A.,Clemens, James A.,Fairhurst, John,Risius, Francesca C.,et al.
, p. 912 - 918 (2007/10/02)
A series of 2-thioether derivatives of a number of clavine alkaloid (ergoline) ring systems have been synthesized and tested for dopamine antagonist activity.Of the compounds tested 2-(methylthio)agroclavine (8,9-didehydro-6,8-dimethyl-2-(methylthio)ergoline) (6) was the most potent and had a profile of activity in animal models indicative of potential antipsychotic activity.The synthesis and biological activity of a number of metabolites of 6, including the 13-hydroxy derivative, are also reported.
TOTAL SYNTHESES OF CLAVINE ALKALOIDS BY AN INTRAMOLECULAR NITRONE-OLEFIN CYCLOADDITION REACTION
Oppolzer, W.,Grayson, J. I.,Wegmann, H.,Urrea, M.
, p. 3695 - 3706 (2007/10/02)
The racemic ergot alkaloids chanoclavine I (1) and 6,7-secoagroclavine (4) have been synthesized stereoselectively from indole-4-carboxaldehyde (7) in overall yields of 14 and 13 percent, respectively.Further syntheses of isochanoclavine I (2), paliclavine (5) and costaclavine (6), via the same isoxazolidine 18 are described.The key step 16-->18 (Scheme 4) involves a transient nitrone 17 which undergoes a kinetically controlled, regio- and stereoselective intramolecular cycloaddition to a 1,2-disubstituted olefinic bond.
Photocyclisation of Enamides. Part 16. A New Synthesis of Clavines. The Stereostructure of Costaclavine
Ninomiya, Ichiya,Kiguchi, Toshiko,Naito, Takeaki
, p. 208 - 211 (2007/10/02)
Epimeric 6,8-dimethylergolines (VI), (VII), and (IX) have been synthesised from the lactam (IVa) which was prepared by the reaction of the enamine (II) with methacryloyl chloride or methacrylamide.The stereochemistry of costaclavine (VI) has been establis
