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Convert the following and show a Mechanism

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It has to be just in a single step and on the arrow head you can't use multiple reagents altogether. Can anyone do it? I am unable to do it in a single step.

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This is my attempt ..! But it is multistep, one step is required ..!

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  • $\begingroup$ This looks like a honework question. Please show us your attempt towards answering the question. $\endgroup$
    – getafix
    Commented Sep 18, 2016 at 6:34
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    $\begingroup$ Singlet oxygen does the trick, if I am not wrong. As far as I can tell, I believe that with typical A-level reagents this conversion is impossible in one step. $\endgroup$
    – orthocresol
    Commented Sep 18, 2016 at 6:43
  • $\begingroup$ What is A level reagent ? $\endgroup$
    – Chloritone_360
    Commented Sep 18, 2016 at 6:45
  • $\begingroup$ Reagents taught in the A level syllabus. $\endgroup$
    – orthocresol
    Commented Sep 18, 2016 at 6:48
  • $\begingroup$ Singlet oxygen conversion: chem.wisc.edu/areas/reich/chem547/2-redox%7B26%7D.htm Articles with this specific reaction: 1 (tBuOOH, some weird catalyst), 2 (O2, Au nanoparticles), 3 (O2, rose bengal, PPh3) $\endgroup$
    – orthocresol
    Commented Sep 18, 2016 at 6:56

1 Answer 1

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You're supposed to turn an alkene into an an allylic alcohol in one step. The "classical" reagent for this conversion is selenium dioxide, $\ce{SeO2}$. Have a look at some older references, such as J. Org. Chem., 1979, 44, 4683-4689. DOI

As kindly pointed out by orthocresol, this elegant method will unfortunately furnish the the wrong allylic alcohol. Whether in situ isomerization is possible (allylic hydroxylation in acidic medium) is feasible can't be decided until I have another coffee ;)

(Please note that a procedure using singlet oxygen will need two steps: the Schenck ene reaction furnishes a hydroperoxide which you would have to reduce.)

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    $\begingroup$ I was under the impression that SeO2 oxidation didn't proceed with transposition of the double bond $\endgroup$
    – orthocresol
    Commented Sep 18, 2016 at 7:35
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    $\begingroup$ @orthocresol You are right and I definitely need another coffee this mormning ;-) $\endgroup$
    – Klaus-Dieter Warzecha
    Commented Sep 18, 2016 at 7:52
  • $\begingroup$ There is a paper which used $\ce{SeO2 + Ac2O}$ ("und Verseifen des erhaltenen Acetats") but it's old and Reaxys won't let me access it. Guillemonat, Annales de Chimie (Cachan, France), 1939, vol. <11> 11, p. 143, 188, 191, 193, 194, 196; Comptes Rendus Hebdomadaires des Seances de l'Academie des Sciences, 1938, vol. 206, p. 1126 $\endgroup$
    – orthocresol
    Commented Sep 18, 2016 at 8:33
  • $\begingroup$ youtu.be/m51VmzjUGRA found this one . Many things about SeO2 though it is in Hindi $\endgroup$
    – Chloritone_360
    Commented Sep 28, 2016 at 6:14

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