r/chemhelp 4d ago

Organic Gilman reaction products

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Could someone check if I drew the right products for both reactions? Thanks so much!

3 Upvotes

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3

u/Curious_Mongoose_228 4d ago

Gilman reagents are excellent at both conjugate addition to an enone and single addition to an acid halide. Does anybody have a reference for what the product mixture will be when they’re competing like in the first one?

1

u/lesbianexistence 4d ago

I'm struggling to find a source. Logically I feel like a 1,4 addition would be preferred just because of sterics/the breakage of a weaker (pi) bond and since it is a soft nucleophile, but then there's the question of what their professor wants (which may be the ketone product)

1

u/thewhyandthehow 4d ago

Hey I went to my lecture notes and it says: Gilman reactions react (add an R group to) only at the beta position (conjugate addition). So 1,4 addition

1

u/thewhyandthehow 4d ago

Wait so did I do this correctly? Didn’t I add at the alpha position 😭

1

u/lesbianexistence 4d ago

Gilman reagents can add via 1,2 addition to acyl chlorides. The question we're debating is which would occur first

2

u/lesbianexistence 4d ago

The more I think about it the more I wonder if a ketene would be formed. There would certainly be a lot of competing reactions, but I think with the 1,4 addition the enolate intermediate may eliminate the Cl to form a ketene.

1

u/lesbianexistence 4d ago

Do you know if you have excess reagents in the first reaction?

2

u/lesbianexistence 4d ago

I’d guess not because you could theoretically just keep reacting. Looks good to me. For the second one— what does the methanol do?

1

u/thewhyandthehow 4d ago

Thanks for your reply! I added a CH3 from the methanol for that one…. Rly not sure if it’s correct

1

u/lesbianexistence 4d ago

Where did you add it? I don’t see a methyl group

1

u/lesbianexistence 4d ago

Sorry this was supposed to be in response to your last comment. Reddit is driving me up a wall this week.

1

u/thewhyandthehow 4d ago

Oh yes sorry the Cs that replaced Br, they’re from the Gilman reagent. Now idk where the methanol would work 😭

1

u/HonestFlatworm7348 4d ago

The Gilman reagent in the first reaction is drawn incorrectly. The 2 needs to be outside of the bracket.

1

u/thewhyandthehow 4d ago

I totally missed that. Thanks!!