With regards to the following synthesis, what are some pros and cons of using hydroboration oxidation followed by oxidation of the alcohols compared to ozonolysis.

More specifically, how do the two compare as to yields of the final product, cost / amount of reagents, speed of reactions, unwanted side reactions?

Here is the synthesis, along with the two ways to prepare the cyclohexadione: enter image description here

  • 2
    $\begingroup$ You lost some carbon atoms in your hydroboration. $\endgroup$
    – Zhe
    Mar 1, 2017 at 23:25
  • $\begingroup$ What Zhe said. Of your two approaches, only one works. Now, there are other oxidative cleavage methods... $\endgroup$
    – Ben Norris
    Mar 2, 2017 at 3:17
  • $\begingroup$ It's not part of your question, but your last line won't work. Alpha bominate carbonyl compounds using $\ce{Br2}$ in acetic acid. You need a base to eliminate the halide, not sulfuric acid. $\endgroup$
    – Ben Norris
    Mar 2, 2017 at 3:30

2 Answers 2


Comparison of the two approaches as far as yield/cost/etc. is void because one of them does not provide the same product as the other. Hydroboration-oxidation of 1,4-dimethylenecyclohexane yields 1,4-bis(hydroxymethyl)cyclohexane with undergoes oxidation to yield 1,4-cyclohexanedicarbaldehyde or 1,4-cyclohexanedicarboxylic acid.

enter image description here

Now, you may be able to take the carbocylic acid, covert to acid halide and then react with $\ce{LiCuMe2}$ to get the ketone, which should undergo Baeyer-Villager oxidation followed by hydrolysis to give the alcohol you want. Or you could covert the diacid to the diamide and subject it to Hofmann degradation to get the amines, which you might be able to convert to the diazo salt with HONO, which may hydrolyze to give the desired diol. Both routes ae significantly more convoluted than ozonolysis, which decreases oveall yield and increases cost.

Now, there are other oxidative cleavage reactions which might be cheaper.


As others have said hydroboration does not give you the product you want.

The major drawback with ozonolysis is having access to the kit and an oxygen supply. A good alternative is the Johnson-Lemieux procedure with Osmium Tetroxide (available encapsulated and much safer than it used to be) and Sodium Periodate. This should give you decent yields of the diketone.


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