Organic Chem Question [Ozonolysis/Oxidation]

[DrTacoElf]

If you have a terminal Alkyne and you add ozone I know it is cleaved into a carboxylic acid + methanoic acid (NOT CO2). However if you have a terminal Alkyne and you add KMnO4 would you get a carboxylic acid + methanoic acid or would you get a carboxylic acid + CO2 (as you would with a terminal alkene)?

Thanks!

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[DrTacoElf]

Any ideas people? I can't find the answer anywhere

 

[Zerconia2921]

If you have a terminal Alkyne and you add ozone I know it is cleaved into a carboxylic acid + methanoic acid (NOT CO2). However if you have a terminal Alkyne and you add KMnO4 would you get a carboxylic acid + methanoic acid or would you get a carboxylic acid + CO2 (as you would with a terminal alkene)?

Thanks!

A terminal alkyne when reacted with O3 forms a CO2 and the rest of the carbon link except the double bond is formed into a carbonyl.

 

[PreDent2009]

If you are talking about propyne with O3, then you would get formic acid and acetic acid as products. If you use KMnO4 on propyne, you will get C02 and acetic acid.

 

[prydA]

kaplan says the following...

O3, CCl4, H2O, react with a terminal alkyne to form a carb. acid and methanoic acid.

KMnO4, OH, reacts with an internal alkyne to form two carb. acids

 

[that guy]

If you have a terminal Alkyne and you add ozone I know it is cleaved into a carboxylic acid + methanoic acid (NOT CO2). However if you have a terminal Alkyne and you add KMnO4 would you get a carboxylic acid + methanoic acid or would you get a carboxylic acid + CO2 (as you would with a terminal alkene)?

Thanks!

like theyve said, terminal alkynes and ozone will yield a carboxylic acid and CO2.

internal alkynes + ozone then h2o are cleaved into 2 carboxylic acids (assuming the number of carbons are not symmetrical)

alkenes are cleaved into ketones and/or aldehydes if ozone work-up under reducing conditions (03 + -78*C, Zn, H2o)

alkenes with ozone and oxidizing conditions (h2o2) will convert the aldehydes into carboxylic acids.. (3-methyl-3heptene cleaved into 2-butone and propionic acid)

alkenes with KMnO4, cold will produce 1,2-diol

alkynes with KMnO4 will produce diketones

alkenes with KMnO4, hot, OH- (or H+) will become carboxylic acids and ketones (OR CO2 if there is a terminal =CH2)

i think those are correct, ridiculous to have to remember those if you ask me.

 

[prydA]

did anyone get any of these questions on the actual DAT? the answers vary everywhere... so how does one know which is real? the kaplan book alone has many diff. answers than the ones you guys posted...