Optically pure product

Discussion in 'DAT Discussions' started by koreano, Jul 12, 2012.

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  1. koreano

    koreano 5+ Year Member

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    I just finished DAT qVAULT orgo test #2 and there is one question that I can't seem to wrap my head around... The question asks, Which of the following reactions will give an optically pure product? And the answer is 2-chloro pentane reacting with NaCN... Can someone explain to me why this is the case?
     
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  3. koreano

    koreano 5+ Year Member

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    Does optically pure product refer to a product that only has ONE chiral center...?
     
  4. ktran17

    ktran17 5+ Year Member

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    read the question wrong =P.. sorry

    was reviewing my notes for chad at the same time and was on the optically inactive section XD
     
    Last edited: Jul 12, 2012
  5. ah7391

    ah7391 Banned

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    No that's wrong.

    Optically pure means it only has one enantiomer. Since this reaction undergoes sn2 -CN is a typical substitution nucleophile for sn2 chemistry then it forms the inverse product only. All the product will have one chiral center.

    Basically you wont have a racemic mixture at all (when both enantiomers are in solution like sn1 chemistry does)
     
  6. koreano

    koreano 5+ Year Member

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    But when you react 2-chloro pentane with NaCN, dont you get 2-methyl-1-pentamine, which has a chiral center at carbon #2?
     
  7. ah7391

    ah7391 Banned

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    And optically INACTIVE is when the product is achiral (or meso, watch out for those!)
     
  8. koreano

    koreano 5+ Year Member

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    I thought so... Thanks ah7391
     
  9. ah7391

    ah7391 Banned

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    Np! Thank chad!
     

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