Jones Oxidation

  • #1

Homework Statement



I am trying to figure out the complete reaction equation for the oxidation of a secondary alcohol, 2-butanol, with CrO3 (and H2SO4).



Homework Equations



See below.

The Attempt at a Solution



In this oxidation, the alcohol is turned into a ketone, not a carboxylic acid, correct?

Therefore, the simple synthesis setup would be:

CH3CH2CH(OH)CH3 + CrO3 + H2SO4 -> CH3CH2C(=O)CH3

Now for the redox reaction with the chromium ions:

(Please note that I am slightly rusty on balancing redox reactions, and I really don’t know if this is remotely valid.)

CrO3 -> Cr(+3)
CH3CH2CH(OH)CH3 -> CH3CH2C(=O)CH3 ??

3 e- + CrO3 + 6 H(+) -> Cr(+3) + 3H2O
CH3CH2CH(OH)CH3 -> CH3CH2C(=O)CH3 + H(+) + 1 e-

3 e- + CrO3 + 6 H(+) -> Cr(+3) + 3H2O
3*(CH3CH2CH(OH)CH3 -> CH3CH2C(=O)CH3 + H(+) + 1 e-)


3 e- + CrO3 + 6 H(+) -> Cr(+3) + 3H2O
3 CH3CH2CH(OH)CH3 -> 3 CH3CH2C(=O)CH3 + 3H(+) + 3 e-
CrO3 + 6 H(+) + 3 CH3CH2CH(OH)CH3 -> Cr(+3) + 3H2O + 3 CH3CH2C(=O)CH3 + 3H(+)

CrO3 + 3 H(+) + 3 CH3CH2CH(OH)CH3 -> Cr(+3) + 3H2O + 3 CH3CH2C(=O)CH3 ?

Thank you.
 

Answers and Replies

  • #3
I just came across this equation for the oxidation in a book.

2CrO3 + 6 H(+) + 3 CH3CH2CH(OH)CH3 -> 2Cr(+3) + 6H2O + 3 CH3CH2C(=O)CH3

Why is it that the bold coefficients are two times more than those in my equation?

Did I do something wrong?

Thanks again.
 
Last edited:
  • #4
chemisttree
Science Advisor
Homework Helper
Gold Member
3,434
463
3 e- + CrO3 + 6 H(+) -> Cr(+3) + 3H2O
CH3CH2CH(OH)CH3 -> CH3CH2C(=O)CH3 + H(+) + 1 e-

Rethink this... pay attention to the hydrogens I have bolded.
 

Related Threads on Jones Oxidation

  • Last Post
Replies
1
Views
3K
Replies
3
Views
610
  • Last Post
Replies
0
Views
2K
  • Last Post
Replies
4
Views
712
Replies
11
Views
11K
  • Last Post
Replies
2
Views
7K
  • Last Post
Replies
7
Views
3K
  • Last Post
Replies
5
Views
643
  • Last Post
Replies
5
Views
69K
  • Last Post
Replies
5
Views
1K
Top