[azmanam]

not in a quantity or quality that able to be isolated.

[robvba]

not in a quantity or quality that able to be isolated.

i was told that we could use OsO4 or MnO4, however, those reagents are not necessary.

any other ideas?

[sjb]

pour HBr into the moat, wait for the reptiles to die, neutralise with the NaOH then swim to safety

Now that's just being obtruse. You may as well say that somewhere in the eye of newt there's an enzyme to convert primary alcohols to the next homologous carboxylic acid....

Hmmm, how does butanol -> n-butyl sulfate -> n-butyl bromide -> grignard -> acid sound?

[robvba]

pour HBr into the moat, wait for the reptiles to die, neutralise with the NaOH then swim to safety

Now that's just being obtruse. You may as well say that somewhere in the eye of newt there's an enzyme to convert primary alcohols to the next homologous carboxylic acid....

Hmmm, how does butanol -> n-butyl sulfate -> n-butyl bromide -> grignard -> acid sound?

would you happen to know the name of the enzyme by any chance?


the acid we're seeking has to have five carbons. any idea of how to get there with what we are given?

[sjb]

would you happen to know the name of the enzyme by any chance?


the acid we're seeking has to have five carbons. any idea of how to get there with what we are given?

Sorry, that was also a bit tongue in cheek. I don't know of any enzyme that will do the job, but that doesn't mean there's not one.

Assuming you can get to the grignard as I suggested, do you know how to convert RMgBr to RCO₂MgBr, and hence to product? I am taking azmanam's approach of assuming we have "any inorganic reagents" (indeed, practically you'll probably need the reagent I'm thinking of for another use)

[robvba]

Assuming you can get to the grignard as I suggested, do you know how to convert RMgBr to RCO₂MgBr, and hence to product? I am taking azmanam's approach of assuming we have "any inorganic reagents" (indeed, practically you'll probably need the reagent I'm thinking of for another use)

R-MgBr + CO2 --> R-COOMgBr

R-COOMgBr + HBr --> R-COOH + Mg²+ + Br₂

??

but how do i isolate CO₂ for this reaction?

[macman104]

CO2 is in the air.  Honestly, you are making this way too complicated.  I don't think your professor meant for you to take this so literally.  Anything in the air, and any metal (any inorganics).

[mreff555]

I don't know the scope of lab equipment available but you could just neutralize an acid and base and capture the evolved CO2.

Assuming you can get to the grignard as I suggested, do you know how to convert RMgBr to RCO₂MgBr, and hence to product? I am taking azmanam's approach of assuming we have "any inorganic reagents" (indeed, practically you'll probably need the reagent I'm thinking of for another use)

R-MgBr + CO2 --> R-COOMgBr

R-COOMgBr + HBr --> R-COOH + Mg²+ + Br₂

??

but how do i isolate CO₂ for this reaction?

[letusgothen]

If you really want ozone badly, you could mix permanganate and sulfuric acid to give Mn₂O₇, which decomposes quickly to MnO₂, oxygen, and ozone, though the stuff's also pretty explosive anywhere above room temperature or through agitation.

[azmanam]

mix permanganate and sulfuric acid to give Mn2O7, which decomposes quickly to MnO2, oxygen, and ozone

about that...

http://www.chemistry-blog.com/2009/02/17/chemistry-lab-demonstrations-upsidedown-thunderstorm/

[aldoxime_amine]

Awesome video!! 
Cool; 

[robvba]

We have access to the following chemicals: THF, H2SO4, HBr, NaOH, NaNH2, 1-butanol, ethanol. And access to: Heat, light, anything in the air, and water.

we need to synthesize pentanoic acid.

Please help me out here. Am i missing anything?

R = CH3CH2CH2CH2

1. 1-butanol + HBr + H2SO4 R-Br + H2O
2. R-Br + Mg + THF R-MgBr
3. R-MgBr + CO2  R-COOMgBr
4. R-COOMgBr + HBr  R-COOH + Mg2+ + Br2

[sjb]

You don't need as strong an acid as HBr to form the carboxylic acid from the carboxyl Grignard, water would be just as good.

Other than that, I'm not over sure that 1-butanol will directly form 1-bromobutane under acid conditions, that's why I suggested going via the sulfate ester and isolating that, as you then form a much better leaving group.

S

[robvba]

You don't need as strong an acid as HBr to form the carboxylic acid from the carboxyl Grignard, water would be just as good.

Other than that, I'm not over sure that 1-butanol will directly form 1-bromobutane under acid conditions, that's why I suggested going via the sulfate ester and isolating that, as you then form a much better leaving group.

S

Like So?

1. 1-butanol + H2SO4 R-HSO4 + H2O
2. R-HSO4 + HBr    R-Br + H2SO4
3. R-Br + Mg + THF R-MgBr
3. R-MgBr + CO2    R-COOMgBr
4. R-COOMgBr + H2O + HBr    R-COOH + Mg2+ + Br2 + H2O

[lutesium]

Why do we have to produce Valeric Acid? Due to his unpleasant odor?
But keep in mind that any spill of the compound into the lab would do the same to you!

Lutesium...