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Topic: Mechanism Worksheet Questions  (Read 10952 times)

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Offline UG

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Re: Mechanism Worksheet Questions
« Reply #15 on: December 05, 2011, 07:03:10 AM »
I've been looking at this for 20 minutes and I still cannot think of a solution given the context of this question :-\
Perhaps someone more knowledgeable will have an idea, unless the question is wrong...

Offline mrkitty

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Re: Mechanism Worksheet Questions
« Reply #16 on: December 05, 2011, 07:05:03 AM »
Haha yeah it is really confusing me. Professor said he would use it to separate the men from the boys. Thanks for trying though.

Offline sjb

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Re: Mechanism Worksheet Questions
« Reply #17 on: December 05, 2011, 07:23:00 AM »
Hi there, I have a problem very (scarily) close to this one.

The question is as follows:

Compound A with a molecular formula of C6H10 decolorizes Br2 and produces a precipitate when reacted with permanganate solution. Hydrogenation with H2 over Pd/C produces B with a formula of C6H12. Reaction of A with peroxyacetic acid produces C, which is highly strained. Hydration of C produces D. Reaction of A with osmium(VIII) oxide followed by work-up produces E which is an isomer of D.  C can also be produced by addition of A to bromine water followed by heating. Ozonolysis of A produces a single product E which is a symmetrical diketone.

Draw structures for A,B,C,D,and E.

This is what I have so far. I am confused because I do not have a mechanism involving heating bromine water. and when I do the ozonolysis of A I do not get the same compound as the E I got from the Os reaction. Any help would be greatly appreciated



If you add Br2 to water, what do you get? Try (mentally) reversing the diketone formation - if you get a ketone what does that tell you about the former double bond?

Offline discodermolide

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Re: Mechanism Worksheet Questions
« Reply #18 on: December 05, 2011, 07:48:57 AM »
All the answers look ok to me except when you ozonolyse cyclohexene you surely get a symmetrical di-aldehyde not a diketone
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Offline sjb

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Re: Mechanism Worksheet Questions
« Reply #19 on: December 05, 2011, 08:36:03 AM »
All the answers look ok to me except when you ozonolyse cyclohexene you surely get a symmetrical di-aldehyde not a diketone

True, but who says A is cyclohexene? I can think of a couple of examples that follow everything else that does not start with this (one is less likely, mind)...

Offline discodermolide

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Re: Mechanism Worksheet Questions
« Reply #20 on: December 05, 2011, 10:12:56 AM »
All the answers look ok to me except when you ozonolyse cyclohexene you surely get a symmetrical di-aldehyde not a diketone

True, but who says A is cyclohexene? I can think of a couple of examples that follow everything else that does not start with this (one is less likely, mind)...

Cyclohexene seems the most likely to me, it can't be that complicated!
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Offline sjb

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Re: Mechanism Worksheet Questions
« Reply #21 on: December 05, 2011, 01:00:24 PM »
All the answers look ok to me except when you ozonolyse cyclohexene you surely get a symmetrical di-aldehyde not a diketone

True, but who says A is cyclohexene? I can think of a couple of examples that follow everything else that does not start with this (one is less likely, mind)...

Cyclohexene seems the most likely to me, it can't be that complicated!


Well, as Sherlock Holmes once said "Eliminate all other factors, and the one which remains must be the truth."

If you end up with a ketone, what does that tell you about the double bond?

Offline Telamond

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Re: Mechanism Worksheet Questions
« Reply #22 on: December 05, 2011, 01:20:17 PM »
You're close to the answer though!
1) You know that your compound is a cyclic alkene.
2) You form a symmetrical diketone upon ozonolysis!

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