TBR Orgo: Hydrogenation

[purplelightning]

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Addition of D2 with Pd catalyst reduces pi bonds by adding deuterium to each pi bond carbon. Treatment of oleic acid with D2 and palladium yields a compound with how many chiral centers?


The answer is two.

I'm not sure as to why. I thought getting rid of the double bond will not produce chiral centers. We'd have 2 hydrogens on each carbons? The key says carbon 8 and 9 are the chiral centers. What about the carbonyl...can that get reduced?


Thanks in advance for the clarification

 

[peacefulheart]

1.I think it produce chiral center after hydrogenation with D2 because of D2 is different from H2.

2. In terms of why the chiral centers are #8 and #9 carbons instead #9 and #10 carbons , I think it is because deuterium is distributed unsymmetrically between the two carbons of former double bond. This is a very complex process.

3. C=O double bond can compete with C=C double bond upon hydrogenation. It depends on catalyst and the shape of catalyst. In general, Pd catalyst favors hydrogenation of C=C double bond

thanks

 

[purplelightning]

Oh duh! We're using deuterium. Thanks so much! 🙂