126822-71-7Relevant 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.
Asymmetric total synthesis of (-)-rasfonin
Bhuniya, Rajib,Nanda, Samik
, p. 1153 - 1165 (2013/02/25)
An efficient chemoenzymatic asymmetric synthesis of pyranone containing natural product (-)-rasfonin is presented here. Enantioselective enzymatic desymmetrization (EED) and a unique Gluconobacter oxydans mediated oxidative kinetic resolution (OKR) have been successfully employed to install three stereocenters (C6′, C7, and C9) of the target molecule. Stereoselective Achmatowicz reaction of a properly decorated furyl nucleus led to the core pyranone structure of rasfonin. At the late stage of the synthesis Negishi coupling has been used to complete the synthesis.
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.
Furan derivatives, method of synthesis and uses thereof
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Page/Page column 16, (2008/12/06)
The present invention relates to furan derivatives of formula (I), their method of synthesis and uses thereof. Concretely, the compounds disclosed have proved to be inhibitors of glycogen synthase kinase 3β, GSK-3 β, which is known to be involved in different disease and conditions, such as Alzheimer's disease or non-insulin dependent diabetes mellitus. The present invention also relates to pharmaceutical compositions comprising the same. Further, the present invention is directed to the use of the compounds in the manufacture of a medicament for the treatment and/or prevention of a GSK-3 mediated disease or condition.
SYNTHESIS OF CHLORINS AND PHORBINES WITH ENHANCED RED SPECTRAL FEATURES
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Page/Page column 124-125; 136, (2008/06/13)
The present invention provides compounds of the general Formula DI: along with methods of making such compounds, formulations containing the same, and methods of using the same (e.g., in photodynamic therapy, for the production of solar cells, etc.).
The furan approach to oxacycles: Synthesis of medium-size 2,3-disubstituted oxacycles
Pérez, Manuel,Canoa, Pilar,Gómez, Generosa,Terán, Carmen,Fall, Yagamare
, p. 5207 - 5209 (2007/10/03)
We describe an efficient new approach for the synthesis of medium-size oxacycles that is based on the oxidation of a furan ring with singlet oxygen followed by an intramolecular Michael addition. This present study enlarges the scope of the furan approach strategy for the synthesis of oxepanes.
The asymmetric synthesis of α-substituted α-methyl and α-phenyl phosphonic acids: Design, carbanion geometry, reactivity and preparative aspects of chiral alkyl bicyclic phosphonamides
Bennani, Youssef L.,Hanessian, Stephen
, p. 13837 - 13866 (2007/10/03)
The design, preparation, structural and spectroscopic analyses of topologically unique and enantiomerically pure alkyl phosphonamides are described. In the case of α-ethyl and α-benzyl phosphonamides, the geometry of both the secondary and tertiary carbanions was determined to be planar through deprotonation/deuteration/alkylation experiments. Stereoselective alkylations of such systems proceeded in good yields and with high diastereoselectivities. The resulting α,α-alkylated phosphonamides were hydrolyzed to give the corresponding α,α-alkyl phosphonic acids with high degrees of enantiomeric purity.
Total synthesis of furanocembranolides. 1. Stereocontrolled preparation of key heterocyclic building blocks and assembly of a complete seco-pseudopterane framework
Paquette, Leo A.,Doherty, Annette M.,Rayner, Christopher M.
, p. 3910 - 3926 (2007/10/02)
A retrosynthetic strategy for the total synthesis of pseudopterolide and allied pseudopteranes is presented. This scheme is dependent upon early elaboration of suitable 2,5-difunctionalized 3-furoate esters. To this end, the pair of useful substrates 21 and 24 was readily synthesized from 2,3-O-isopropylidene-D-glyceraldehyde and methyl 4-(phenylthio)acetoacetate. The conversion of both of these intermediates into furanolactone 27 was next studied. The best method for gaining suitable control of stereochemistry involved condensation of 24 with methyl 3-formylpropionate under conditions of boron trifluoride catalysis. Transformation of the (phenylthio)methyl substituent of 27 into the requisite isopentenyl side chain was next accomplished in five steps. Because alkylation α to the lactone carbonyl in 46 could be realized only in modest yield, this final segment of the intended macrocyclic ring was introduced earlier by more convergent means. Indeed, the coupling of 24 to 52 proved to be efficient and highly diastereoselective. Following an unsuccessful attempt to introduce the isopentenyl side chain after elaboration of the butenolide subunit, the chemical sequence was reversed. The dual selenenylation strategy for oxidation of both relevant pendant groups was notably effective for this purpose. The subsequent chemospecific attachment of the isobutenyl fragment onto bromide 62 was achieved by palladium(0)-catalyzed coupling to a vinylstannane in a process that promises considerable versatility. Further chemical manipulation gave rise to the seco-pseudopterane 71, thereby completing the intermediate stages of the total synthesis of the pseudopterane ring system.
