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Chemistry Forums for Students => Organic Chemistry Forum => Topic started by: Stiffa_Basirio on February 26, 2022, 05:29:43 AM

Title: Organic synthesis
Post by: Stiffa_Basirio on February 26, 2022, 05:29:43 AM
Hello! Our professor asked us to make up a full synthesis of some ogranic sompounds and explain which reactions should be used and why. My organic chemistry knowledge is very suboptimal and I struggle to even find where to start, so any help would be appreciated. The only tip we were given that the compound's synthesis was based on a reaction bearing the name of a scientist  ???

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Title: Re: Organic synthesis
Post by: Aldebaran on February 26, 2022, 05:46:24 PM
If you are struggling where to start you might start by searching synthesis of cyclic ketones and ethers on the internet.
Title: Re: Organic synthesis
Post by: rolnor on February 27, 2022, 05:39:38 PM
If you know little chemistry this is not trivial. This can be a start:

https://en.m.wikipedia.org/wiki/1,3-Cyclohexanedione


Maybe react this with dibromomethyl butene?
Title: Re: Organic synthesis
Post by: wildfyr on March 03, 2022, 01:23:05 PM
That internal double bond strikes me as a tough one. Is this a paper exercise or a real one?
Title: Re: Organic synthesis
Post by: rolnor on March 04, 2022, 05:54:33 AM
Agree, this is hard even if you have good chem knowledge. Is a enol-ether
Title: Re: Organic synthesis
Post by: OrganicH2O on March 20, 2022, 11:40:28 AM
Would this work? Step 1 is Michael addition using NaH. Use mild enough conditions that it stops at only the Michael, and does not do a Robinson. Step 2 is to add more NaH to form the next most stable position to have an enolate, creating a dienolate. Step 3 is to add 1 equivalent Br2, or another electrophilic bromine source, to react selectively at the more basic of the two enolates. Step 4 is for the structure to hopefully cyclize naturally via Sn2 at the enolate oxygen. Using sodium as a spectator ion should help in reacting more selectively at oxygen. Step 4 is a Wittig that should be selective for the desired ketone because the other ketone is a vinylogous ester and should be much less reactive.

Ultimately, this is really just two steps, with some waiting in between. Add 1 mol NaH, let it do the Michael. Add another mol NaH to make the next enolate. Add 1 mol Br2, let it cyclize. Then work-up. Then do the Wittig.
Title: Re: Organic synthesis
Post by: Babcock_Hall on March 20, 2022, 04:59:58 PM
It would be nice to see more work from the OP.
Title: Re: Organic synthesis
Post by: billnotgatez on March 20, 2022, 05:04:46 PM
Quote from: Babcock_Hall on March 20, 2022, 04:59:58 PM
It would be nice to see more work from the OP.

Last Active:February 28, 2022, 10:48:18 AM

I think the OP just wanted a quick answer and never came back

added later
Just makes me sad
Title: Re: Organic synthesis
Post by: OrganicH2O on March 21, 2022, 06:40:49 PM
I was just bored and had fun solving it. And I was curious if anyone more knowledgeable than me had a critique. I felt like I was getting a little too creative there. I figured the OP was long gone, or at least hoped the assignment had already come due...
Title: Re: Organic synthesis
Post by: kriggy on March 22, 2022, 04:11:21 AM
Quote from: OrganicH2O on March 21, 2022, 06:40:49 PM
I was just bored and had fun solving it. And I was curious if anyone more knowledgeable than me had a critique. I felt like I was getting a little too creative there. I figured the OP was long gone, or at least hoped the assignment had already come due...

Your conditions will probably yield Robinson annulation product. Not sure if you could make the selective bromination and stuff.
Title: Re: Organic synthesis
Post by: Stiffa_Basirio on April 10, 2022, 11:40:12 AM
So sorry for not checking this thread, I was doing some other work while stretching out the deadline haha. All that I could figure out is that one of the main substances should be C1CC(=O)CC(=O)C1 and another one some sort of diene. My prof said that probably more likely would be Michael reaction, but that's all I could find :(
(Very sorry once again, forgot to turn on notifications of any sort on this forum)
Title: Re: Organic synthesis
Post by: Stiffa_Basirio on April 10, 2022, 12:17:23 PM
That's what I came up with, by no means I am sure this is right or viable.
Title: Re: Organic synthesis
Post by: rolnor on April 11, 2022, 12:54:18 AM
The cyclohexadione was my suggestion.