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Organic Chemistry Multistep Synthesis

  • #1

Homework Statement


http://i.imgur.com/H8p56.jpg

2. The attempt at a solution

I'm not quite sure how to start this one... I would assume organolithiation could get me started for the two combining, but I'm not quite sure how to get the 3' carbon to spout that ehtyl group or how to eliminate the oxygen. Any help?
 

Answers and Replies

  • #2
Char. Limit
Gold Member
1,204
14
My organic chemistry book says to always think backwards: ask yourself, "what compound undergoing what reaction would give me my final product?"

In that case, I'd be tempted to consider ozonolysis as the final step...
 
  • #3
I can't imagine that would be the final step... We definitely have not used that in any of our synthesis problems yet, and I looked it up and I can't see how ozonolysis could lead to that...

Did you see that it goes Desired product --> Starting materials?
 
  • #4
Char. Limit
Gold Member
1,204
14
No... I saw an arrow and assumed that the stuff it was pointing to was the product.

Nevertheless, the principle holds. First think I'd do is remove (or add on in the last step) your methyl ether. Of course, it's also possible, as your first step, to use a... actually, I know of no reactions that reverse the effect of alkene cleavage...
 
Last edited:
  • #5
I would do that, but I'm not good enough at it yet where I can see ten steps in reverse =/.

Okay I don't even know if I'm beginning right, but let's say we add Et2CuLi with an H+ workup to the one on the left to get the ethyl on the bottom... I'm not quite sure how to swap out the oxygen w/ the other reactant. Getting the methyl on the reactant on the right is easy at the end, I'm just not sure...
 
  • #6
445
5
I'm not saying it's the right way, but a couple of words spring out when I try to do the question. Wittig and Umpolung.

I assume that as there is no chirality shown that racemates are desired.
 
  • #7
Hmm could you possibly explain what race mates are?

And yes this is very likely; those two are on topic with what we have recently learned... I keep chuggin at it
 
  • #8
445
5
Are you aware of stereoisomerism? What do you understand by umpolung and Wittig, then?
 

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