187458-29-3Relevant academic research and scientific papers
Synthetic Studies on Alotamide A: Construction of N-Demethylalotamide A
Domínguez, Marta,Román, David,Souto, José A.,de Lera, ángel R.
supporting information, p. 6057 - 6070 (2021/12/10)
Several approaches to the synthesis of cyclodepsipeptide natural product alotamide A are described, eventually affording a very advanced N-demethylated analogue of the targeted natural product. The difficulties found in our endeavors on the synthesis of alotamide A have allowed us to gather some valuable information regarding the most convenient synthetic step for each key transformation. The intramolecular Csp2?Csp2 Stille cross-coupling and the macrolactam formation were found to be reliable protocols for the final construction of the alotamide A skeleton.
Biselyngbyolides A & C: their total synthesis and anticancer activities
Chakrabarti, Partha,Goswami, Rajib Kumar,Mandal, Pratiti,Paul, Debobrata,Sahana, Moinul Haque
, p. 7151 - 7164 (2020/10/02)
Convergent strategies for the first total synthesis of biselyngbyolide C and an alternative route for the total synthesis of biselyngbyolide A have been developed. The key strategic feature in this study is Heck macrocyclization. The use of intramolecular Heck coupling for biselyngbyolide B was demonstrated by us earlier; however such a strategy has not been explored further for the other members of this family of natural products, in particular, where sensitive skipped olefins are involved. The other highlights of this synthetic study include iterative Crimmins acetate aldol and Wittig olefination processes, followed by the less explored cobalt-hydride-based reduction of an activated olefin and Shiina esterification. Our synthetic study enabled us to amend the reported NMR data of biselyngbyolides A and C. An evaluation of the anticancer activities of both biselyngbyolides A and C revealed that the apoptosis generated in cancer cells followed an intrinsic pathway.
Cyclodepsipeptide alveolaride C: Total synthesis and structural assignment
Saha, Sanu,Paul, Debobrata,Goswami, Rajib Kumar
, p. 11259 - 11265 (2020/11/04)
First stereoselective total synthesis of naturally occurring bioactive cyclodepsipeptide alveolaride C has been achieved using a convergent approach. This synthetic study enabled us to establish unambiguously the stereochemistry of three unassigned chiral centres embedded in the nonpeptidic segment as well as revised the stereochemistry of the proposed β-phenylalanine counterpart of the molecule. The key strategic features of this synthesis include Sharpless asymmetric dihydroxylation for installing the vicinal diol moiety, Julia-Kocienski olefination for constructing the aliphatic side chain, the Shiina protocol for intermolecular esterification, amide coupling and macrolactamization for the ring formation. This journal is
Stereoselective Total Synthesis of Bioactive Marine Natural Product Biselyngbyolide B
Das, Sayantan,Paul, Debobrata,Goswami, Rajib Kumar
supporting information, p. 1908 - 1911 (2016/05/19)
A convergent strategy for the stereoselective total synthesis of biologically active marine natural product biselyngbyolide B has been developed. Key strategies of this synthesis include Jamison protocol of trans-hydroalumination/allylation for installation of C18-C23 olefin moiety and intramolecular Heck coupling for macrocyclization.
Anaerobic nitroxide-catalyzed oxidation of alcohols using the NO +/NO· redox pair
Holan, Martin,Jahn, Ullrich
supporting information, p. 58 - 61 (2014/01/23)
A new method for alcohol oxidation using TEMPO or AZADO in conjunction with BF3·OEt2 or LiBF4 as precatalysts and tert-butyl nitrite as a stoichiometric oxidant has been developed. The system is based on a NO+/NO· pair for nitroxide reoxidation under anaerobic conditions. This allows the simple, high-yielding conversion of various achiral and chiral alcohols to carbonyl compounds without epimerization and no formation of nonvolatile byproducts.
Stereoselective synthesis of a C1-C18 fragment of amphidinolides G and H
García-Fortanet, Jorge,Formentín, Pilar,Díaz-Oltra, Santiago,Murga, Juan,Carda, Miguel,Alberto Marco
, p. 3192 - 3196 (2013/04/24)
A stereoselective synthesis of a C1-C18 segment of the structure of the cytotoxic macrolides amphidinolides G and H is reported. The target compound was retrosynthetically disconnected into three fragments. In the synthetic sense, connection of the fragme
Enantioselective synthesis of the C5-C23 segment of biselyngbyaside
Chandrasekhar, Srivari,Rajesh, Gontla,Naresh, Tumma
supporting information, p. 252 - 255 (2013/02/23)
Stereo and enantioselective synthesis of C5-C23 fragment of cytotoxic marine natural product biselyngbyaside is achieved using E-selective methyl lithium addition onto enyne, Crimmin's acetate aldol reaction, Sharpless asymmetric epoxidation, and Julia-Kocienski olefination as the key steps.
Total synthesis of the anti-apoptotic agents Iso- And bongkrekic acids
Francais, Antoine,Leyva, Antonio,Etxebarria-Jardi, Gorka,Ley, Steven V.
supporting information; experimental part, p. 340 - 343 (2010/03/25)
(Figure presented) The first convergent total synthesis of isobongkrekic acid is reported involving three different stereospecific palladium cross-couplings for the formation of the diene units. Access to bongkrekic acid by this route is also demonstrated. These syntheses involve the formation of several potentially general building blocks.
Total syntheses of amphidinolides B1, B4, G1, H1 and structure revision of amphidinolide H2
Fuerstner, Alois,Bouchez, Laure C.,Morency, Louis,Funel, Jaques-Alexis,Liepins, Vilnis,Poree, Francois-Hugues,Gilmour, Ryan,Laurich, Daniel,Beaufils, Florent,Tamiya, Minoru
experimental part, p. 3983 - 4010 (2009/12/22)
Dinoflagellates of the genus Amphidinium produce a "library" of closely related secondary metabolites of mixed polyketide origin, which are extremely scarce but highly promising owing to the exceptional cytotoxicity against various cancer cell lines. Because of the dense array of sensitive functionalities on their largely conserved macrocyclic frame, however, these amphidinolides of the B, D, G and H types elapsed many previous attempts at their synthesis. Described herein is a robust, convergent and hence general blueprint which allowed not only to conquest five prototype members of these series, but also holds the promise of making "non-natural" analogues available by diverted total synthesis. This notion transpires for a synthesis-driven structure revision of amphidinolide H2. The successful route hinges upon a highly productive Stille-Migita cross-coupling reaction at the congested and chemically labile 1,3-diene site present in all such targets, which required the development of a modified chloride- and fluoride-free protocol. The macrocyclic ring could be formed with high efficiency and selectivity by ring-closing metathesis (RCM) engaging a vinyl epoxide unit as one of the reaction partners. Because of the sensitivity of the targets to oxidizing and reducing conditions as well as to pH changes, the proper adjustment of the protecting group pattern for the peripheral -OH functions also constitutes a critical aspect, which has to converge to silyl groups only once the diene is in place. Tris(dime-thylamino)sulfomum difluorotrimethyl-silicate (TASF) turned out to be a sufficiently mild fluoride source to allow for the final deprotection without damaging the precious macrolides.
Enantioselective organocatalytic conjugate reduction of β-AzoleContaining α,β-unsaturated aldehydes
Hoffman, Thomas J.,Dash, Jyotirmayee,Rlgby, James H.,Arseniyadis, Stelllos,Cossy, Janine
supporting information; experimental part, p. 2756 - 2759 (2009/11/30)
β-Azole-contalnlng α,β-unsaturated aldehydes were successfully reduced under highly enantloselectlve organocatalytlc transfer hydrogenation conditions. The products were obtained In good yields and up to 94% optical purity. This simple process was success
