Matches in DBpedia 2014 for { <http://dbpedia.org/resource/Wieland–Miescher_ketone> ?p ?o. }
Showing items 1 to 23 of
23
with 100 items per page.
- Wieland–Miescher_ketone abstract "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 reaction 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 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 in the 1960s and 1970s. Wieland–Miescher ketone contains the AB-ring structure of steroids and is for this reason an attractive starting material for the steroid skeleton, an approach used in one successful synthesis of adrenosterone.The original Wieland–Miescher ketone is racemic and prepared in a Robinson annulation of 2-methyl-1,3-cyclohexanedione and methyl vinyl ketone. The intermediate alcohol is not isolated. The required 2-methyl-1,3-cyclohexanedione can be prepared from resorcinol by hydrogenation over Raney nickel to dihydroresorcinol as the enolate followed by alkylation with methyl iodide.An enantioselective synthesis employs L-proline as an organocatalyst: This reaction appeared in 1971 in the patent literature by Z. G. Hajos and D. R. Parrish. In this patent, the isolation and characterization of the above pictured optically active intermediate bicyclic ketol (in parentheses) has also been described, because they worked at ambient temperature in anhydrous dimethylformamide (DMF) solvent. Working in DMSO solvent does not allow isolation of the bicyclic ketol intermediate, it leads directly to the optically active bicyclic dione. The reaction is called the Hajos-Parrish reaction or the Hajos-Parrish-Eder-Sauer-Wiechert reaction.This reaction has also been performed in a one-step procedure, leading to 49% yield and 76% Enantiomeric excess (ee):Wieland Miescher Barbas 2000Other proline-based catalysts have been investigated".
- Wieland–Miescher_ketone thumbnail Wieland-Miescherketone.svg?width=300.
- Wieland–Miescher_ketone wikiPageID "3241211".
- Wieland–Miescher_ketone wikiPageRevisionID "599319495".
- Wieland–Miescher_ketone imagefile "Wieland-Miescherketone.svg".
- Wieland–Miescher_ketone imagesize "120".
- Wieland–Miescher_ketone iupacname "8".
- Wieland–Miescher_ketone subject Category:Ketones.
- Wieland–Miescher_ketone subject Category:Naphthalenes.
- Wieland–Miescher_ketone type ChemicalCompound.
- Wieland–Miescher_ketone type ChemicalSubstance.
- Wieland–Miescher_ketone type ChemicalObject.
- Wieland–Miescher_ketone type Thing.
- Wieland–Miescher_ketone comment "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.".
- Wieland–Miescher_ketone label "Wieland-Miescher-Keton".
- Wieland–Miescher_ketone label "Wieland–Miescher ketone".
- Wieland–Miescher_ketone label "维兰德-米舍尔酮".
- Wieland–Miescher_ketone sameAs Wieland%E2%80%93Miescher_ketone.
- Wieland–Miescher_ketone sameAs Wieland-Miescher-Keton.
- Wieland–Miescher_ketone sameAs Q413602.
- Wieland–Miescher_ketone sameAs Q413602.
- Wieland–Miescher_ketone wasDerivedFrom Wieland–Miescher_ketone?oldid=599319495.
- Wieland–Miescher_ketone depiction Wieland-Miescherketone.svg.