OChem2Ch9

Card Set Information

Author:
victimsofadown
ID:
201998
Filename:
OChem2Ch9
Updated:
2013-03-14 12:34:19
Tags:
OChem2Test1
Folders:

Description:
OChem2Ch9
Show Answers:

Home > Flashcards > Print Preview

The flashcards below were created by user victimsofadown on FreezingBlue Flashcards. What would you like to do?


  1. Hydrohalogenation [alkene]

    HX
    ---->
    • Addition of H and X across 2x bond
    • Markovnikov
    • Racemic Mixture
    • Rearrangement possible
    • MECHANISM: Proton transfer from HBr to 2x bond.  Nucleophilic attack by HBr on newly-formed carbocation.
  2. Hydrohalogenation [alkene]

    HBr
    ---->
    ROOR
    • Addition of H and Br across 2x bond
    • Anti-markovnikov
    • Racemic Mixture
    • No rearrangement
    • MECHANISM: Radical mechanism
  3. Acid-catalyzed hydration [alkene]

    H3O+
    ----->
    • Addition of H and OH across 2x bond
    • Markovnikov
    • Racemic mixture
    • Rearrangement possible
    • Reversable - excess acid favors alkene, excess H2O favors alcohol
    • MECHANISM: 2x bond grabs H from H3O+, creates carbocation, rearranges, H2O attacks, H2O attacks the newest C+ leaving OH
  4. Oxymercuration-demercuration [alkene]

    1) Hg(OAc)2, H2O
    ----------------->
    2) NaBH4
    • Addition of H and OH across 2x bond
    • Markovnikov
    • Racemic mixture
    • No rearrangement
    • MECHANISM: Mercurium ion intermediate
  5. Hydroboration-oxidation [alkene]

    1) BH3*THF
    ------------->
    2) HOOH, NaOH
    • Addition of H and OH across 2x bond
    • Anti-markovnikov
    • Syn addition (but only trans product)
    • MECHANISM: H on BH3 is replaced with the less-substituted end of alkene, H goes to other end.  Repeated for all three H's until BR3 is seen.   Creates three sets of ROH.
  6. Catalytic Hydrogenation [alkene]

    H2
    ---->
    Pt
    • Alkene to alkane
    • Syn addition
    • NOTE - Wilkinson's catalyst is a soluble catalyst that will work in the same manor
  7. Bromination (Halogenation) [alkene]

    Br2
    ----->
    • Addition of Br2 across 2x bond
    • Anti-addition
    • MECHANISM: Formation of bromonium ion
    • NOTE - solvent must be inert (no water!)
    • NOTE - also viable for Cl2
  8. Halohydrin Formation [alkene]

    Br2
    ---->
    H2O
    • Addition of Br and OH across 2x bond
    • Markovnikov
    • Anti addition
    • MECHANISM: H2O makes second attack, because it is more prevalent than Br-
  9. Dihydroxylation [alkene]

    1) RCO3H
    ----------->
    2) H3O+
    • Addition of OH and OH across 2x bond
    • Anti-addition
    • MECHANISM: alkene -> epoxide using peracid.  Acid or base catalyzed ring opening.  (same results, diff mech).
    • NOTE - step 1 could also be MCPBA
    • NOTE - step 2 could also be base
  10. Dihydroxylation [alkene]

    1) OsO4
    --------->
    2) Na2SO4/H2O
    • Addition of OH and OH across 2x bond
    • Syn addition
    • MECHANISM: Osmate ester intermediate
    • NOTE - Step 2 can be replaced with NMO for cost purposes
    • NOTE - reaction can be done with KMnO4 / NaOH at cold temp, for much less $$ and less toxicity BUT yield will suffer
  11. Ozonolysis [alkene]

    1) O3
    ------->
    2) DMS
    • Cleavage across the 2x bond, creating ketone or aldehyde
    • MECHANISM: Molozonide intermediate -> ozonide intermediate
    • NOTE - when using KMnO4 + heat similar rxn occurs, but aldehydes are oxidized to acids.
    • NOTE - Step 2 could be (CH3)2S

What would you like to do?

Home > Flashcards > Print Preview