Miescher

Additional applications are exemplified by the well-known Meystre-Miescher degradation of the bile acid side chain and, more recently, in the preparation of a-pyrones from a,iS-unsaturated lactones. ... 

E. F. Hoppe-Seyler and F. Miescher isolated " nuclein , the Hrst nucleic acid, from pus. 

Miescher, K. and Klarer, W. U.S. Patent 2,449,241 September 14, 194B assigned to Ciba Pharmaceutical Products, Inc. 

Miescher, G.M., U.S. Patent 3,001,912 September 26, 1961 assigned to Commercial Solvents Corp. 

Miescher, K. and Scholz, C. U.S. Patent 2 05,627 June 25,1940 assigned to the Society of Chemical Industry in Basle, Switzerland... 

The so-called Wieland-Miescher ketone is a valuable starting materia) used in the synthesis of steroid hormones. How might you prepare it hom 1,3-cycio-hexanedione ... 

Kagi, H. Miescher, K. Helv. Chim. Acta (HCACAV) 32, 2489 (1949). 

The Robinson annulation is a valuable method for preparing bicyclic and tricyclic structures that can serve as starting materials for the preparation of steroids and terpenes.175 Reaction with 2-methylcyclohexan-l,3-dione gives a compound called the Wieland-Miescher ketone. 

Compound 23-V is known as the Wieland-Miescher ketone and can be obtained by Robinson annulation of 2-methylcyclohexane-l,3-dione. 

Longifolene has also been synthesized from ( ) Wieland-Miescher ketone by a series of reactions that feature an intramolecular enolate alkylation and ring expansion, as shown in Scheme 13.26. The starting material was converted to a dibromo ketone via the Mr-silyl enol ether in the first sequence of reactions. This intermediate underwent an intramolecular enolate alkylation to form the C(7)—C(10) bond. The ring expansion was then done by conversion of the ketone to a silyl enol ether, cyclopropanation, and treatment of the siloxycyclopropane with FeCl3. 

The synthesis of S. J. Danishefsky s group is outlined in Scheme 13.55. The starting material is a protected derivative of the Wieland-Miescher ketone. The oxetane ring is formed early in this synthesis. An epoxide is formed using dimethylsulfonium methylide (Step A-3) and opened to an allylic alcohol in Step A-4. The double bond... 

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