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Thursday, July 07, 2005

Pinacol Rearrangement

The pinacol rearrangement is essentially a dehydration reaction of an alcohol, specifically a diol. The following is an example of a pinacol rearrangement in which the (R,R)-diol (TBDMS is tert-butyldimethylsilyl) was allowed to react with 2,2 dimethylpropane (2,2-DMP) in the presence of boron trifluoride etherate at room temperature. This particular reaction was done in order to attain the acetone derivative.

Interestingly, instead of retaining its chirality, the product of the pinacol arrangement actually resulted in a racemic mixture. Subsequent derivatives of this product eventually yield benzophenone (hydroxyphenstatin), which, biologically, is a potent antitumor and antimitotic agent. Accordingly, hydroxyphenstatin has also been proven to inhibit tubulin assembly. Article Link.

6 Comments:

  • 1) the Pinacol rearrangement does not involve loss of a carbon, as you have in the scheme
    2) where did you get 100C/H2SO4?
    3) there is no journal in CiteULike

    By Blogger Jean-Claude Bradley, at 7:24 AM  

  • 4) If you use an abbreviation like TBDMS specify what it is in the text.
    5) Always link an ether through the oxygen, never the carbon (i.e. OCH3-R is wrong; CH3O-R is right)

    By Blogger Jean-Claude Bradley, at 7:29 AM  

  • 1) the reaction is still wrong
    2) you must show reagents on the arrow

    By Blogger Jean-Claude Bradley, at 6:36 AM  

  • i still have to fix the reaction in respect to chirality... i just haven't had access to chemsketch

    By Blogger shailja, at 11:01 AM  

  • It is not a chirality problem. How do you get an extra carbon in a Pinacol Rearragement?

    By Blogger Jean-Claude Bradley, at 11:08 AM  

  • 9/10 marks. DMP abbreviation wrong.

    By Blogger Jean-Claude Bradley, at 6:54 AM  

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