This is the follow-up to the previous post exploring a typical nucleophilic addition-elimination reaction. Here is the elimination step, which as before requires proton transfers. We again adopt a cyclic mechanism to try to avoid the build up of charge separation during those proton movements.
Well, this particular sequence of events is clearly not the full (or even a partial) answer to the mechanism of the second elimination step for this reaction. We know this because it predicts far too large a barrier. Something is missing from this model, and that something is probably a polarizing group such as HCl. Watch this space.
In the mid to late 1990s as the Web developed, it was becoming more obvious…
I have written a few times about the so-called "anomeric effect", which relates to stereoelectronic…
The recent release of the DataCite Data Citation corpus, which has the stated aim of…
Following on from my template exploration of the Wilkinson hydrogenation catalyst, I now repeat this…
In the late 1980s, as I recollected here the equipment needed for real time molecular…
On 24th January 1984, the Macintosh computer was released, as all the media are informing…
View Comments
Good afternoon
I'm performing this reaction and everything occurs very well, but I have one question that no paper I have read ansewered: why does the cis isomer is formed rather than trans? In my reaction I have a ratio of 85:15 of cis over trans. I have read a lot of papers but all f them show that this result is the usual but none of them gives an explanation. If you could help me it wuld be great.
Thank you
You would have to specify what the two substituents are that enable cis and trans to be differentiated. Only then could e.g. an 85:15 ratio be explained.
The reaction is with 2-(non-8-enyl)-cyclopentanone, and then I get the cis prefered product of the oxime. The papers I have been reading shows that usually with the cyclics systems the cis product is formed preferentially over trans but there are no explanation why. Thank you for your help.