174199-01-0Relevant academic research and scientific papers
Deletion of the C26 Methyl Substituent from the Bryostatin Analogue Merle 23 Has Negligible Impact on Its Biological Profile and Potency
Zhao, Xiguang,Kedei, Noemi,Michalowski, Alexandra,Lewin, Nancy E.,Keck, Gary E.,Blumberg, Peter M.
, p. 1049 - 1059 (2018/05/31)
Important strides are being made in understanding the effects of structural features of bryostatin 1, a candidate therapeutic agent for cancer and dementia, in conferring its potency toward protein kinase C and the unique spectrum of biological responses that it induces. A critical pharmacophoric element in bryostatin 1 is the secondary hydroxy group at the C26 position, with a corresponding primary hydroxy group playing an analogous role in binding of phorbol esters to protein kinase C. Herein, we describe the synthesis of a bryostatin homologue in which the C26 hydroxy group is primary, as it is in the phorbol esters, and show that its biological activity is almost indistinguishable from that of the corresponding compound with a secondary hydroxy group.
Synthesis of trisaccharides by hetero-diels-alder welding of two monosaccharide units
Himanen, Jatta A.,Pihko, Petri M.
supporting information; experimental part, p. 3765 - 3780 (2012/09/25)
A new strategy for the synthesis of di- and trisaccharides based on the de novo synthesis of the linking saccharide unit is presented. In this strategy, functionalized monosaccharide building blocks already incorporating the glycosidic linkages are welded together using a metal-catalyzed hetero-Diels-Alder (HDA) reaction to generate a new monosaccharide unit between them. The highest yields and selectivities in the HDA reaction were obtained by using chiral Schiff base chromium complexes. Disaccharide products were accessible by reaction of Danishefsky's diene with acetyl- and benzyl-protected galactoside aldehydes. For the synthesis of trisaccharide products, acetyl-protected glucose or galactose-derived dienes were fused with monosaccharide-derived aldehydes using chromium catalysts for the HDA reaction. The desired trisaccharide products were obtained in moderate to good yields with excellent stereoselectivity. The central pyranulose-ring generated in the process possessed an L-cis-enulose configuration according to NMR spectroscopy and modeling studies. 1 + 1 equals 3! The hetero-Diels-Alder union of two functionalized monosaccharide building blocks - one bearing an aldehyde and the other a readily accessible diene moiety - affords functionalized trisaccharide structures in moderate to good yields and excellent stereoselectivities when β-anomers of the aldehydes are used. Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.
A convenient access to γ-lactones from O-allyl-α-bromoesters using a one-pot ionic-radical-ionic sequence
Beneteau, Romain,Lebreton, Jacques,Denes, Fabrice
supporting information; experimental part, p. 1516 - 1520 (2012/09/08)
Cognac in the jar! An efficient one-pot sequence for the preparation of γ-lactones is described. Following reduction of α-bromo ester precursors with DIBAL-H and radical cyclization of the resulting O-aluminum acetals, a preparative in-situ Oppenauer-type oxidation of the cyclic O-aluminum acetal using simple aldehydes or ketones gives access to γ-lactones in high yields. Copyright
Radical cyclization of α-bromo aluminum acetals onto alkenes and alkynes (radic[al] process): A simple access to γ-lactols and 4-methylene-γ-lactols
Boussonniere, Anne,Beneteau, Romain,Zimmermann, Nicolas,Lebreton, Jacques,Denes, Fabrice
supporting information; experimental part, p. 5613 - 5627 (2011/06/22)
An efficient preparation of γ-lactols and methylene-γ-lactols is described. Highly acid-sensitive lactols are prepared in a concise manner by using a radical cyclization of aluminum acetals. The precursors for the radical reactions are readily prepared fr
Radical cyclization of α-bromo aluminum acetals: An easy approach to γ-lactols
Boussonniere, Anne,Denes, Fabrice,Lebreton, Jacques
supporting information; experimental part, p. 9549 - 9552 (2010/03/25)
[Chemical equation presented] Running rings around aluminum: An efficient procedure for radical cyclization α-bromo esters is reported. Reduction of the esters by DIBAL-H at low temperature gives aluminum acetals, which are cyclized in the presence of nBu
Intramolecular opening of β-lactams with amines as a strategy toward enzymatically or photochemically triggered activation of lactenediyne prodrugs
Banfi, Luca,Guanti, Giuseppe,Rasparini, Marcello
, p. 1319 - 1336 (2007/10/03)
In order to develop a general strategy for selective activation of designed enediyne prodrugs belonging to the "lactenediyne" family, we studied the scope of intramolecular transamidation of simple monocyclic β-lactams bearing a tethered amine. The effect of substituents, of reaction media, and of the type of tether, on the rate of transamidation is disclosed. The possibility of triggering the transamidation event under mild conditions by the action of suitable enzymes or UV light was demonstrated on model monocyclic β-lactams. Finally, the strategy of intramolecular opening of the β-lactam leading to a larger seven-membered ring was employed on a lactenediyne, demonstrating that ring enlargement could unleash the reactivity of the enediyne moiety. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003.
