Results 41 to 50 of about 8,953 (240)
On the proposed structures and stereocontrolled synthesis of the cephalosporolides
Beilstein Journal of Organic Chemistry, 2012 The synthesis of four candidate stereoisomers of cephalosporolide H is described, made possible by a zinc-chelation strategy for controlling the stereochemistry of oxygenated 5,5-spiroketals.
Sami F. Tlais, Gregory B. Dudley
doaj +1 more source
Aplicação de espectrometria de massas com ionização por elétron na análise de alcaloides do mulungu
Química Nova, 2012 Erythrina verna is a medicinal plant used to calm agitation popularly known as mulungu. We purchased the barks of E. verna from a commercial producer and analyzed the alkaloid fraction of the bark by CG-MS and HRESI-MS.
Luís Guilherme Pereira Feitosa +5 more
doaj +1 more source
Chemistry – A European Journal, EarlyView.Integrin αVβ3‐targeting small‐molecule drug conjugates (SMDCs) were synthesized by conjugating a cryptophycin payload through a neutrophil elastase‐cleavable NPV‐PABC linker. RGD peptidomimetic and linker epimers served as controls for targeting and enzymatic cleavage, and the resulting conjugates displayed subnanomolar cytotoxicity in vitro.
Dominic Seißenschmidt +3 more
wiley +1 more source
Molecules, 2002 Diethyl 1,2-benzoxaphosphorine-3-carboxylates 5 undergo a regio- and stereoselective [2+2] photodimerization reaction in methanol solution under the action of sunlight, giving in all cases the corresponding anti head-to-tail dimers 6 and 7.
Anka Bojilova +3 more
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Synthetic Epimers of Ajmaline and Isoajmaline
Zeitschrift für Naturforschung B, 1996 Two new epimers of ajmaline (1) and isoajmaline (2) were synthesized by means of tosylation followed by hydrolysis with NaOH/CH3OH. Displacement of tosyl with hydroxyl group yielded C21 epimers of these alkaloids. The structures were identified by various spectroscopic techniques.
M. Ataullah Khan, Humaira Raees
openaire +1 more source
Stereochemical Control in the Matteson Reaction
Chemistry – A European Journal, EarlyView.The Matteson homologation is a highly versatile method for the stereoselective insertion of carbenoids into boronic esters. Through iterative application of the process, complex chiral molecules can be synthesized. The stereoselectivity of the reaction is determined by a chiral diol incorporated in the boronic ester.
Hae Mo Lee, Christoph Hirschhäuser
wiley +1 more source
New syntheses of (±)-tashiromine and (±)-epitashiromine via enaminone intermediates
Beilstein Journal of Organic Chemistry, 2016 The syntheses of the naturally occurring indolizidine alkaloid (±)-tashiromine and its unnatural epimer (±)-epitashiromine are demonstrated through the use of enaminone chemistry.
Darren L. Riley +2 more
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N‐Sulfonyl Azalevoglucosan: A Versatile Platform for the Synthesis of Polysubstituted Piperidines
Chemistry – A European Journal, EarlyView.Gain by strain: The synthesis of a levoglucosan analog, in which the pyranose oxygen has been replaced by a nitrogen, allows navigation on the piperidine ring to iteratively install functional groups at C1, C2, C3, C4, and C6 positions using simple experimental protocols with minimal protecting group manipulation.
Dylan Yorga +6 more
wiley +1 more source
Clinical Pharmacology &Therapeutics, EarlyView.Pregnancy‐associated breast cancer (PrBC) presents therapeutic challenges. Understanding maternal–fetal safety of systemic anticancer therapies is critical. We performed a case/non‐case disproportionality analysis using the WHO global pharmacovigilance database up to January 2024, to evaluate maternal–fetal outcomes associated with breast cancer (BC ...
Rayan Kabirian +12 more
wiley +1 more source
(1S)-1,2-O-Benzylidene-α-d-glucurono-6,3-lactone
Acta Crystallographica Section E, 2009 X-ray crystallographic analysis has established that the major product from the protection of d-glucoronolactone with benzaldehyde is (1S)-1,2-O-benzylidene-α-d-glucurono-6,3-lactone, C13H12O6, rather than the R epimer.
David J. Watkin +5 more
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