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Wittig reaction

12 real reactions from the literature, on phosphonium salts, aliphatic aldehydes and hemiacetals. Each scheme shows starting materials, conditions and products, with the yield and reference where the source reports them.

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  1. Wittig: triphenyl(4-triphenylphosphaniumylbutyl)phosphanium (a phosphonium salt) with 2.2 equiv.; acetone gives 2,7-dimethyl-2,6-octadiene (the trisubstituted alkene). 81% yield.
    WittigOrganometallics 2014, 33, 3235

  2. Wittig: triphenyl(phenylmethyl)phosphonium (a phosphonium salt) with 1); 2) gives [(E)-1,4-diphenylbut-1-en-3-yn-2-yl]benzene (the trisubstituted alkene). 80% yield.
    WittigChem. Commun. 2019, 55, 7808

  3. Wittig: 2,2,2-trifluoroacetophenone (an aryl ketone) and 2-oxopropyl(triphenyl)phosphanium (a phosphonium salt) with Et3N; DMF; 80 °C gives (E)-4-phenyl-5,5,5-trifluoro-3-pentene-2-one (the trisubstituted alkene). 90% yield.
    WittigOrg. Lett. 2016, 18, 3538

  4. Wittig: propyltriphenylphosphonium bromide (a phosphonium salt) and ethyl levulinate (a methyl ketone) with 1) nBuLi, THF, 0 C; 2) add ketoester gives ethyl (E)-4-methylhept-4-enoate (the trisubstituted alkene). 52% (E) yield.
    WittigTetrahedron Lett. 2009, 50, 5719

  5. Wittig: ethyl(triphenyl)phosphonium (a phosphonium salt) with 1); 2) gives cis-2-phenyl-2-butene (the trisubstituted alkene). 73% yield.
    WittigJ. Org. Chem. 2015, 80, 11388

  6. Wittig: 1-(4-methylphenyl)ethanone (an aryl ketone) and (3-bromopropyl)triphenylphosphonium (a phosphonium salt) with 2 equiv NaH gives 1-(1-cyclopropylideneethyl)-4-methylbenzene (the tetrasubstituted alkene). 83% yield.
    WittigJ. Chem. Soc., Chem. Commun. 1994, 499

  7. Wittig: isopropyltriphenylphosphonium (a phosphonium salt) and 1-(4-methylphenyl)ethanone (an aryl ketone) with tBuOK; DMSO; PhMe; 110 °C gives 1-methyl-4-(3-methylbut-2-en-2-yl)benzene (the tetrasubstituted alkene). 86% yield.
    WittigOrg. Lett. 2019, 21, 807

  8. Wittig: (ethoxycarbonylmethyl)triphenylphosphonium (a phosphonium salt) with 1); 2); 1 equiv. gives ethyl 3-methyl-4-oxopent-2-enoate (the trisubstituted alkene). 55% yield.
    WittigGreen Chem. 2017, 511

  9. Wittig: phenylglyoxal (a dialkyl ketone) and (3,3-dimethyl-2-oxobutyl)-triphenylphosphanium (a phosphonium salt) with tBuOK; PhMe gives (E)-5,5-dimethyl-1-phenylhex-2-ene-1,4-dione (the trans-1,2-disubstituted alkene). 82% yield.
    WittigJ. Chem. Soc., Perkin Trans. 1 1996, 2837

  10. Wittig: an aliphatic aldehyde with MePPh3+I-, NaHMDS gives the terminal alkene.
    WittigOrg. Lett. 2005, 7, 705

  11. Wittig: 2-hydroxytetrahydropyran (a hemiacetal) gives (E)-ethyl 7-hydroxy-2-methyl-2-heptenate (the trisubstituted alkene).
    WittigJ. Org. Chem. 2002, 67, 9443

  12. Wittig: an aliphatic aldehyde with Check, some Woodward paper gives the trans-1,2-disubstituted alkene.
    WittigRealOChem worksheet