At 3:30 the elimination of the alcohol should have happened in 2 steps where the first step is the deprotonation and the second one is the leaving of -OH. It is the special E1cb mechanism that's happening here.
Hello, thanks for your videos. A question, in 8:19, why do the electrons collapse to form a double bond ( and pushing the other double bond onto the Oxygen) instead of collapsing on the Carbon like the other aldol condensations?
both of the structures you described are in resonance with each other so what he wrote and what you are describing are equally correct. it is more formally seen as how he wrote it in the video
+Julia Källberg Hydroxide, and H2O are typically better leaving groups and contribute to the system for further reactions. H2O protonating and -OH deprotonating.
You can remember it this way. A weak base is a good leaving group. Since H2O is a stronger acid than an alkane, therefore it's conjugate base(OH-)is weaker than that of the alkane
At 3:30 the elimination of the alcohol should have happened in 2 steps where the first step is the deprotonation and the second one is the leaving of -OH. It is the special E1cb mechanism that's happening here.
Yes and the whole reaction shouldn't be reversible because of that step
Hello, thanks for your videos. A question, in 8:19, why do the electrons collapse to form a double bond ( and pushing the other double bond onto the Oxygen) instead of collapsing on the Carbon like the other aldol condensations?
both of the structures you described are in resonance with each other so what he wrote and what you are describing are equally correct. it is more formally seen as how he wrote it in the video
Why is KOH a weak base? I thought KOH was a strong base due to strong bases being group 1 hydroxides?
May I synthesise 2,6-dimethylhex-2-enone from 5-oxo-4-methylheptanal via intramolecular aldol condensation?
thanks so much for this video
why there is no deprotonation on c 3 at 3:32?
How come the OH group leaves and not the methyl? better leaving group?
+Julia Källberg Hydroxide, and H2O are typically better leaving groups and contribute to the system for further reactions. H2O protonating and -OH deprotonating.
You can remember it this way. A weak base is a good leaving group. Since H2O is a stronger acid than an alkane, therefore it's conjugate base(OH-)is weaker than that of the alkane
The weakest base is the leaving group. Alkyl pka 45-70 and pka of OH ~ 29. so the hydroxide is the weaker base and leaving.
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