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
O, w/u to have the Grignard we made attach on this CO2
as a Carboxylic Acid
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+
How do you turn a Carboxylic Acid into a Primary Alcohol?
You can add BH3
(which is a H-
O , 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)
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!)
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-)
How can you turn an Alcohol into a Nitrile?
NaCN will turn an Alcohol into a Nitrile
What can you do with a Nitrile group (once it's added on)?
Nitriles can be turned into Carboxylic Acids
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-]).
What does PBr3 do?
- PBr3 replaces an OH with a Br
- (this is useful for turning an Alcohol (OH) into a Grignard Reagent!)
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!)