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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. 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.

  5. 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 ...

  6. Büchner–Curtius–Schlotterbeck reaction - Wikipedia

    en.wikipedia.org/wiki/Büchner–Curtius...

    The Buchner–Curtius–Schlotterbeck reaction is the reaction of aldehydes or ketones with aliphatic diazoalkanes to form homologated ketones. [1] It was first described by Eduard Buchner and Theodor Curtius in 1885 [ 2 ] and later by Fritz Schlotterbeck in 1907. [ 3 ]

  7. The Foul Flirting Method of Male Ring-Tailed Lemurs - AOL

    www.aol.com/foul-flirting-method-male-ring...

    Although there are more than 100 species of lemurs, the ring-tailed lemur is arguably the most well-known thanks to King Julien in the hit children’s film Madagascar. His need to “move it ...

  8. Ex-FBI informant accused of lying about Bidens agrees to ...

    www.aol.com/ex-fbi-informant-accused-lying...

    A former FBI informant accused of lying about President Joe Biden and his son Hunter Biden’s alleged business dealings with a Ukrainian energy company has agreed to plead guilty to federal ...

  9. FDA Issues Urgent Warning on Dangers of Common Dog Medication

    www.aol.com/fda-issues-urgent-warning-dangers...

    The United States Food and Drugs Administration is warning pet owners about a common medication given to pets to treat arthritis. The F.D.A. now says that the drug Librela may be associated with ...