Chemical Forums
Chemistry Forums for Students => Organic Chemistry Forum => Topic started by: MuscarineChloride on April 21, 2021, 05:21:55 AM
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Hello everyone,
I habe been trying to reproduce a reduction reaction of an ethylester (Benzyl-Ethyllactate) to an aldehyde using DiBAL-H in Ethylether at -78 °C in Dry solvents but have been getting basically no product, the solvents an the glasware are dry and the DiBAL-H is new. Also no alcohol is present...
Any suggestions why my reduction isnt working? The Literature reports up to 80-90 % isolated yield for the same reaction.
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Is diethyl ether the solvent used in the reference?
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yes diethylether is also the solvent in the refrence
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Do you have NMR of the starting ester?
Do you monitor the reaction in some way, TLC?
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How dry is your starting material?
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Yes i have a NMR of the startung ester, it fits the refrence.
I can monitor the reaction by TLC an massspec.
The starting material should be dry, it is dried after the extraction with Na2SO4 and then purifyed on a sillica column, I will dry it a second time and give it an noter try!
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How does it look on MS?
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There are other more experienced synthetic chemists here than I am. However, I will share my thoughts. When I first started to use Dibal-H to attempt the reduction of a Weinreb amide, we obtained poor results. Much later and with a different batch of Dibal-H, we obtained better yield. It might or might not have been the Dibal-H itself; it could easily have been other aspects of our technique.
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Maybe give it a little extra ass kicking by doing at higher temp?