81703-93-7Relevant academic research and scientific papers
An approach to the carbon backbone of bielschowskysin, part 1: Photocyclization strategy
Himmelbauer, Martin,Farcet, Jean-Baptiste,Gagnepain, Julien,Mulzer, Johann
, p. 8214 - 8244 (2014/01/06)
Several macrocyclization reaction attempts of highly advanced precursors toward a total synthesis of marine diterpene bielschowskysin are disclosed. Biomimetic [2+2]-photocyclization reactions were applied to construct the cyclobutane core in these intermediates, which could be accessed along scalable high-yielding reaction sequences from cheap enantiopure starting-materials. Asymmetric syntheses of various highly functionalized intermediates toward the total synthesis of bielschowskysin (1) are described. In particular a biomimetic [2+2]-photocycloaddition reaction strategy, forming the cyclobutane core, was followed by various macrocyclization reactions attempts. Copyright
1,2-diastereoselective C-C bond-forming reactions for the synthesis of chiral β-branched α-amino acids
Spangenberg, Thomas,Schoenfelder, Angele,Breit, Bernhard,Mann, Andre
experimental part, p. 6005 - 6018 (2011/02/25)
SN2′ sequences have been employed for the synthesis of β-branched α-amino acids using 1,2-diastereocontrol for forming C-C bonds. An oxazolidine fragment derived from Garner's aldehyde provides the handle for facial discrimination and acts as a
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.
scheme or table, 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).
Synthesis of γ-lactones by desymmetrization. A synthesis of (-)-muricatacin
Teresa Barros,Adilia Januario Charmier,Maycock, Christopher D.,Michaud, Thierry
experimental part, p. 396 - 399 (2009/04/06)
A short synthesis of the natural potent cytotoxic agent (-)-muricatacin 1 and related unsaturated lactones from a versatile common intermediate, dienedioate 2, derived from d-mannitol or tartaric acid, is described. The strategy depends upon the desymmetrization of 7 by dihydroxylation and elaboration of the hydroxy alkyl sidechain. A route to unsaturated lactones is also described using a cis selective Wittig reaction. Since the enantiomers of 2 are available from the corresponding tartaric acids, this method provides access to both enantiomers of the described compounds and a wide range of derivatives.
Process for preparing alpha, beta - unsaturated ester
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Page/Page column 5, (2008/06/13)
A process for preparing an α,β-unsaturated ester of the compound (4), wherein R7 and R8 are the same or different and hydrogen atom, C1-6alkyl group or phenyl group, which comprises oxidizing a glycerol derivative (2), wherein R7 and R8 are the same as defined above, in the presence of a nitroxyl radical compound and a co-oxidant to prepare a glyceraldehyde and then reacting the compound with a phosphonoacetic acid alkyl ester or a (triphenylphosphoranylidene)acetic acid alkyl ester to give the compound (4).
Stereoselective photochemical 1,3-dioxolane addition to 5-alkoxymethyl-2(5H)-furanone: Synthesis of bis-tetrahydrofuranyl ligand for HIV protease inhibitor UIC-94017 (TMC-114)
Ghosh, Arun K.,Leshchenko, Sofiya,Noetzel, Marcus
, p. 7822 - 7829 (2007/10/03)
A convenient synthesis of (3R,3aS,6aR)-3-hydroxyhexahydrofuro[2,3-b]furan, a high-affinity non-peptidal ligand for HIV protease inhibitor UIC-94017, is described. This inhibitor is undergoing advanced clinical trials. The synthesis utilizes a novel stereoselective photochemical 1,3-dioxolane addition to 5(S)-benzyloxymethyl-2(5H)-furanone as the key step. The requisite furanone derivative was prepared in high enantiomeric excess by an immobilized lipase-catalyzed selective acylation of (±)-1-(benzyloxy)-3-buten-2-ol and a ring-closing olefin metathesis with Grubbs' catalyst. Optically active bis-THF was converted to protease inhibitor 2 (UIC-94017).
Direct access to furanosidic eight-membered ulosonic esters from cis-α,β-epoxy aldehydes
Sugisaki, Claudia H.,Ruland, Yvan,Baltas, Michel
, p. 672 - 688 (2007/10/03)
Direct access to bicyclic precursors of octulosonic acids is achieved by treatment of differentially (or not) protected γ,δbis(silyloxy) cis-α,β-epoxy aldehydes with ethyl 2-(trimethylsilyloxy)-2-propenoate in the presence of boron trifluoride-diethyl ether. An X-ray crystallographic structure of a bicycle (compound 33a) was obtained and used to determine the absolute configurations of the different stereogenic centers and thus the diastereoselective preference of the aldol reaction (syn) and the regioselectivity of the epoxide ring-opening (C-6 atom). Functionalization and opening of the bicyclic compound to afford octulosonic analogues in their furanoside forms was studied. An octulosonic 8-phosphate analogue has been synthesized. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003.
An improved synthesis of (4S)-4,5-O-isopropylidenepent- (2Z)-enoate
Koenig, Stefan G.,Loewe, Ralf S.,Austin, David J.
, p. 1379 - 1383 (2007/10/03)
(4S)-4,5-O-Isopropylidenepent-(2Z)-enoate (1) has been prepared on a multigram scale from 1,2: 5,6-di-O-isopropylidene-D-mannitol (4) in a one pot, two step sequence with improved selectivity (16:1 Z:E) and yield (71% Z) over previous literature procedures.
Synthesis of analogues of the marine anti-tumour agent curacin
Martin, Barbara K. D.,Mann, John,Sageot, Olivia A.
, p. 2455 - 2460 (2007/10/03)
A concise, multigram synthesis of (4R)-2-[(1′R2′S)-1′, 2′-methano-3′-(/er/-butyldiphenylsiloxy)propyl]-4-hydroxymethyl-4, 5-dihydrothiazole has been achieved, and this compound has been used for the production of a range of analogues of the anti-mitotic a
