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Cyclization Cascade (cyclization + cascade)

Distribution by Scientific Domains
Chemistry100%

Selected Abstracts

A Dialdehyde Cyclization Cascade: An Approach to Pleuromutilin,

ANGEWANDTE CHEMIE, Issue 49 2009
Matthew
Nacheinander reagieren die Aldehydgruppen von 1 beim Aufbau des Gerüsts 2 des antibakteriellen Naturstoffs Pleuromutilin in einer SmI2 -vermittelten Cyclisierungskaskade, die vollständig diastereoselektiv zwei Ringe und vier benachbarte Stereozentren liefert. [source]

ChemInform Abstract: Synthesis of 4-Allylquinazolines from N-(2-Cyanoaryl)amides via the In-Mediated Allylation of Nitrile and Dehydrative Cyclization Cascade.

CHEMINFORM, Issue 36 2010
Sung Hwan Kim
Abstract The sequence yields 4-allylquinazolines (III) and (V). [source]

ChemInform Abstract: Gold(I)-Catalyzed Divergence in the Reactivity of 3-Silyloxy 1,6-Enynes: Pinacol-Terminated vs Claisen-Terminated Cyclization Cascades.

CHEMINFORM, Issue 45 2008
Baburaj Baskar
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]

Mechanistic insights into oxidosqualene cyclizations through homology modeling

JOURNAL OF COMPUTATIONAL CHEMISTRY, Issue 6 2003
Gasch, Tanja Schulz
Abstract 2,3-Oxidosqualene cyclases (OSC) are key enzymes in sterol biosynthesis. They catalyze the stereoselective cyclization and skeletal rearrangement of (3S)-2,3-oxidosqualene to lanosterol in mammals and fungi and to cycloartenol in algae and higher plants. Sequence information and proposed mechanism of 2,3-oxidosqualene cyclases are closely related to those of squalene-hopene cyclases (SHC), which represent functional analogs of OSCs in bacteria. SHCs catalyze the cationic cyclization cascade converting the linear triterpene squalene to fused ring compounds called hopanoids. High stereoselectivity and precision of the skeletal rearrangements has aroused the interest of researchers for nearly half a century, and valuable data on studying mechanistic details in the complex enzyme-catalyzed cyclization cascade has been collected. Today, interest in cyclases is still unbroken, because OSCs became targets for the development of antifungal and hypocholesterolemic drugs. However, due to the large size and membrane-bound nature of OSCs, three-dimensional structural information is still not available, thus preventing a complete understanding of the atomic details of the catalytic mechanism. In this work, we discuss results gained from homology modeling of human OSC based on structural information of SHC from Alicyclobacillus acidocaldarius and propose a structural model of human OSC. The model is in accordance with previously performed experimental studies with mechanism-based suicide inhibitors and mutagenesis experiments with altered activity and product specificity. Structural insight should strongly stimulate structure-based design of antifungal or cholesterol-lowering drugs. © 2003 Wiley Periodicals, Inc. J Comput Chem 24: 741,753, 2003 [source]