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Epoxidation of Alkene with mCPBA
6:59 — by Heath G.

Tip: This isn't the place to ask a question because the teacher can't reply.

Key Questions

  • Answer:

    Asymmetric epoxidation (also called the Sharpless epoxidation reaction) is a method of preparing chiral epoxides from prochiral allylic alcohols.


    It uses a catalyst containing either (+)- or (-)-diethyl tartrate to form the chiral epoxide in greater than 90 % enantiomeric excess.

    The oxidizing agent is tert-butyl hydroperoxide.

    The catalyst is prepared from titanium tetra(isopropoxide), #"Ti"["OCH"("CH"_3)_2]_4#.

    It binds the hydroperoxide, the allylic alcohol group, and the chiral tartrate ligand through the oxygen atoms.

    A "simplified" Jmol image of the complex (below) shows how an #"O"# atom of the hydroperoxide is preferentially pointed towards one face of the alkene.

    (Adapted from chemtube3d)

  • Answer:

    The reaction of alkenes with peroxides is often called an epoxidation reaction.


    It is sometimes called the Prilezhaev reaction, after the Russian chemist who discovered it in 1909.

    The reaction involves the action of a peroxyacid with an alkene to form an epoxide.

    You can read more about this reaction in the Socratic answer to What is epoxidation of alkenes?.

  • Answer:

    Well, you take an olefin, and make a three-membered ring...........


    And from the three-membered epoxide ring, once ring-opened, you can get TWO functionalized sites.

    And these days, epoxidation is not only highly chemically efficient and selective, it is increasingly highly stereochemically selective. Look up #"Sharpless peroxidation"#, which won for its inventor, Barry Sharpless, a Nobel prize in 2001.