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  2. Buchner ring expansion - Wikipedia

    en.wikipedia.org/wiki/Buchner_ring_expansion

    The Buchner ring expansion is a two-step organic C-C bond forming reaction used to access 7-membered rings. The first step involves formation of a carbene from ethyl diazoacetate , which cyclopropanates an aromatic ring.

  3. Ring expansion and contraction - Wikipedia

    en.wikipedia.org/wiki/Ring_expansion_and_contraction

    The strategy can start with a Simmons-Smith-like cyclopropanation of a cyclic alkene. [8] A related cyclopropane-based ring expansion is the Buchner ring expansion. The Buchner ring expansion is used to convert arenes to cycloheptatrienes. The Buchner ring expansion is encouraged to open to the desired product by placing electron withdrawing ...

  4. Carbene - Wikipedia

    en.wikipedia.org/wiki/Carbene

    Carbenes had first been postulated by Eduard Buchner in 1903 in cyclopropanation studies of ethyl diazoacetate with toluene. [29] In 1912 Hermann Staudinger [30] also converted alkenes to cyclopropanes with diazomethane and CH 2 as an intermediate. Doering in 1954 demonstrated their synthetic utility with dichlorocarbene. [31]

  5. Cyclopropanation - Wikipedia

    en.wikipedia.org/wiki/Cyclopropanation

    Cyclopropanation is also stereospecific as the addition of carbene and carbenoids to alkenes is a form of a cheletropic reaction, with the addition taking place in a syn manner. For example, dibromocarbene and cis -2-butene yield cis -2,3-dimethyl-1,1-dibromocyclopropane, whereas the trans isomer exclusively yields the trans cyclopropane.

  6. Gift shopping? These 25 Cyber Monday sales work for ... - AOL

    www.aol.com/lifestyle/cyber-monday-gifts-sale...

    The time to shop for Christmas gifts is now: Take advantage of these great Cyber Monday sales. (Ariel Skelley via Getty Images)

  7. 'Top Chef' holiday ham is sweet and spicy: Here's the recipe ...

    www.aol.com/top-chef-holiday-ham-sweet-100040850...

    Prepare the ham. 1. Preheat your oven to 325 degrees Fahrenheit. 2. Place the ham cut-side down in a roasting pan. Bake the ham. 3. Insert cloves into the ham, spacing them 1 inch apart.

  8. Texas sues New York doctor accused of posting abortion pills

    www.aol.com/texas-sues-york-doctor-accused...

    Texas has sued a New York doctor for allegedly prescribing abortion pills to a Dallas-area woman, launching the first known legal challenge of its kind, which will test what happens when two ...

  9. Metal-catalyzed cyclopropanations - Wikipedia

    en.wikipedia.org/wiki/Metal-catalyzed_cyclopropa...

    Cyclopropanation of olefins with diazocarbonyl compounds is commonly accomplished using rhodium carboxylate complexes, although copper was originally used. [11] The scope of the olefin is generally quite broad—electron-rich, [ 12 ] neutral, [ 13 ] and electron-poor [ 14 ] olefins have all been cyclopropanated efficiently using rhodium-based ...