Chem 124 Exam #3 Reaction Rules (Carboxylic Acids)

Card Set Information

Chem 124 Exam #3 Reaction Rules (Carboxylic Acids)
2013-04-22 10:51:27
Chem 124 Exam Reaction Rules Carboxylic Acids

Chem 124 Exam #3 Reaction Rules (Carboxylic Acids)
Show Answers:

  1. How can you extend an [Alkyl Halide] chain and add a Carboxylic Acid to the [new] end?
    • Need a partial positive Carbon at end that you're going to extend (ex: C-Cl).
    • THEN, just add CN- , H+ , H2O, w/u to add a Carboxylic Acid group on to the [new] end


    IF have a Br at end of chain that you want to extend (i.e. R-R-R-Br) then add an Mg (i.e. make the chain a grignard), then add a CO2 w/ H+, H2O, w/u to have the Grignard we made attach on this CO2 as a Carboxylic Acid
  2. How can you convert an Alkyl Halide (i.e. R-Br) into a Carboxylic Acid?
    You can add KMnO4 , H2O , H+ , Δ


    You can add NaOH to the partial positive Carbon (thus kicking off the Br and replacing it with OH (Sn2) ==> making a primary alcohol) and then adding CrO3 , H+
  3. How do you turn a Carboxylic Acid into a Primary Alcohol?
    You can add BH3 (which is a Hsource), H+ , H2O , w/u


    • You can add LiAlH4 , H+ , H2O , w/u
    • (remember the +AlH3 just gets grabbed by the O- and makes the O leave, leaving a Carbocation which then gets attacked by the 2nd H- from the LiAlH4)
  4. How can you turn a Carboxylic Acid into an Ester?
    • You can add an alcohol (ex: CH3OH) , H+
    • (the HO-CH3 just protonates the OH from the Carboxylic Acid and with the help of the resonating O-, kicks out the OH, leaving behind an Ester)
    • (remember that you'd rather have an OH- in solution than a VERY unstable CH3-.. which is what CH3Br's (Grignards) are)


    • (more tricky)
    • Add an NaOH to the solution (which - being a "strong" base - will deprotonate the OH from the Carboxylic Acid, yield a Carboxide -- O- hanging on the Carboxyl), then add a Grignard Reagent (e.g. CH3Br) which has a +CH3 that will get attacked by the O- and get added onto the O-, yielding an Ester!)
  5. How do you turn an Alcohol into an Ether (or Ester)?
    Just add an alcohol (R-R...-OH) with H+!

    (the Alcohol that you add will attack the Carbonyl Carbon, then the H from the OH you added will transfer to the old alcohol, and the H+ will stabilize the Carbonyl O-)
  6. How can you turn an Alcohol into a Nitrile?
    NaCN will turn an Alcohol into a Nitrile
  7. What can you do with a Nitrile group (once it's added on)?
    Nitriles can be turned into Carboxylic Acids
  8. How do you turn Nitriles into Carboxylic Acids (once the Nitrile is added on first of course)?
    H+ , H2O will turn a Nitrile into a Carboxylic Acid

    (side note: if you add a Base instead of an acid like we did above [ex: if you added NaOH], then you just turn the Nitrile into a Carboxide ion instead [COO-]).
  9. What does PBr3 do?
    • PBr3 replaces an OH with a Br
    • (this is useful for turning an Alcohol (OH) into a Grignard Reagent!)
  10. What does R..-CuLi do to Carboxyl groups (i.e. CO-Cl [aka: Acid Halide])?
    • R..-CuLi simply replaces the Halide with whatever R..- is with the CuLi!
    • (there has to be a Halide present however!)