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Wieland–Miescher Ketone
The Wieland–Miescher ketone is a racemic bicyclic diketone (enedione) and is a versatile synthon which has so far been employed in the total synthesis of more than 50 natural products, predominantly sesquiterpenoids, diterpenes and steroids possessing possible biological properties including anticancer, antimicrobial, antiviral, antineurodegenerative and immunomodulatory activities. The reagent is named after two chemists from Ciba Geigy, Karl Miescher and Peter Wieland (not to be confused with Heinrich Otto Wieland). Examples of syntheses performed using the optically active enantiomer of this diketone as a starting material are that of ancistrofuran and the Danishefsky Taxol total synthesis, Danishefsky total synthesis of Taxol. Most advances in total synthesis methods starting from Wieland–Miescher ketone were fueled by the search for alternative methods for the industrial synthesis of contraceptive and other medicinally relevant steroids, an area of research that flourished ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sigma-Aldrich
Sigma-Aldrich (formally MilliporeSigma) is an American chemical, life science, and biotechnology company that is owned by the German chemical conglomerate Merck Group. Sigma-Aldrich was created in 1975 by the merger of Sigma Chemical Company and Aldrich Chemical Company. It grew through various acquisitions until it had over 9,600 employees and was listed on the Fortune 1000. The company is headquartered in St. Louis and has operations in approximately 40 countries. In 2015, the German chemical conglomerate Merck Group acquired Sigma-Aldrich for $17 billion. The company is currently a part of Merck's life science business and in combination with Merck's earlier acquired Millipore Corporation, Millipore, operates as MilliporeSigma. History Sigma Chemical Company of St. Louis and Aldrich Chemical Company of Milwaukee were both American specialty chemical companies when they merged in August 1975. The company grew throughout the 1980s and 1990s, with significant expansion in fac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
