[xshadow]

Hi

I have some doubts about these examples:


If I have an excess of RLi:

I'll get A) product
I'll get B) product

Will the excess of  organolithium  react with the esteric group?

Same doubts for the hydrolysis Reaction
Some explanation?

Thanks!!

[rolnor]

I am looking att the reaction A, there could be a chance of this material reacting further, can you se what could happen? You have a alkoxide and a ester in the same molecule.

[xshadow]

I am looking att the reaction A, there could be a chance of this material reacting further, can you se what could happen? You have a alkoxide and a ester in the same molecule.

Speaking  about product A:

If I have RLi in excess then can it "reduce" the ester into an alcoholic group?

Or  do you mean   the alcoholic  group which is formed in the A product in the reaction between ketone and organolithium?
(Perhaps  later deprotonated by the excess of RLi??)

Anyway:
Alcohol+ ester = "" transesterification""

Here both the functional group are on the same molecule so I could get a 5 membered ring?
But  can RLi also react with ester after having reacted with
the keto group?? (Because I know that  usually an organolithium  can react witch an ester also,attacking the electrophilic C=O carbon)

Thanks

[rolnor]

Yes, you probably get the 5-membered ring, a lactone. I think lithiumacetylide can react with ester if you have high temperature.
If one acetylide react with ester, what would the first product be?

[xshadow]

Yes, you probably get the 5-membered ring, a lactone. I think lithiumacetylide can react with ester if you have high temperature.
If one acetylide react with ester, what would the first product be?

Here my answer:


An easter that reacts with 1 equivalent of organolithium RLi give a keton

But ketone are much more reactive than ester so the reaction continiues with a second equivalent of RLi


Isn't this correct?
Thanks

[rolnor]

Yes, its correct. I have not worked with lithium acetylide but normaly this is how organolithiums react.