A Novel Route to 5-Substituted 3-Isoxazolols. Cyclization of <i>N,O-</i>DiBoc β-Keto Hydroxamic Acids Synthesized via Acyl Meldrum's Acids
作者:Ulrik S. Sørensen、Erik Falch、Povl Krogsgaard-Larsen
DOI:10.1021/jo991409d
日期:2000.2.1
We have found that N, O-diBoc-protected beta-keto hydroxamicacids can be synthesized and cyclized to 5-substituted 3-isoxazolols without formation of any byproduct. We present a novel and versatile three-step procedure in which carboxylic acid derivatives are converted into acyl Meldrum's acids which, upon aminolysis with N, O-bis(tert-butoxycarbonyl)hydroxylamine, lead to the N, O-diBoc-protected
Palladium-catalysed substitution reactions of geminal allylic diacetates
作者:Fanie R. van Heerden、Johan J. Huyser、D. Bradley、G. Williams、Cedric W. Holzapfel
DOI:10.1016/s0040-4039(98)01000-4
日期:1998.7
The Pd(0)-catalysed substitution of allylic 1,1-diacetates by both carbon and oxygen nucleophiles is described. The products isolated resulted from either single or double substitution reactions.
Synthesis of the Tetracyclic Core of the Neomangicols Using a Late-Stage Indene Alkylation
作者:Jessica L. Wood、Brian G. Pujanauski、Richmond Sarpong
DOI:10.1021/ol9010008
日期:2009.7.16
A general approach to the tetracyclic core of the neomangicol natural products via a late-stage indene alkylation reaction is presented. This strategy sets the stage for access to the neomangicol family and, in addition, provides a potential biogenetically inspired entry to the mangicol natural products.
作者:Marcello Allegretti、Riccardo Bertini、Maria Candida Cesta、Cinzia Bizzarri、Rosa Di Bitondo、Vito Di Cioccio、Emanuela Galliera、Valerio Berdini、Alessandra Topai、Giuseppe Zampella、Vincenzo Russo、Nicoletta Di Bello、Giuseppe Nano、Luca Nicolini、Massimo Locati、Piercarlo Fantucci、Saverio Florio、Francesco Colotta
DOI:10.1021/jm049082i
日期:2005.6.1
The CXC chemokine CXCL8/IL-8 plays a major role in the activation and recruitment of polymorphonuclear (PMN) cells at inflammatory sites. CXCL8 activates PMNs by binding the seven-transmembrane (7-TM) G-protein-coupled receptors CXC chemokine receptor 1 (CXCR1) and CXC chemokine receptor 2 (CXCR2). (R)-Ketoprofen (1) was previously reported to be a potent and specific noncompetitive inhibitor of CXCL8-induced human PMNS chemotaxis. We report here molecular modeling studies showing a putative interaction site of 1 in the TM region of CXCR1. The binding model was confirmed by alanine scanning mutagenesis and photoaffinity labeling experiments. The molecular model driven medicinal chemistry optimization of 1 led to a new class of potent and specific inhibitors of CXCL8 biological activity. Among these, repertaxin (13) was selected as a clinical candidate drug for prevention of post-ischemia reperfusion injury.
Stereoselective Synthesis of Woody Fragrances Related to Georgyone and Arborone
作者:Erik J. Hicken、E. J. Corey
DOI:10.1021/ol8000359
日期:2008.3.1
The synthesis of two very powerful and pleasant new odorants has been carried out from a common intermediate.