Pinacol pinacolone rearrangement

Question

I was reading the topic alcohol in that I saw a reaction Pinacol pinacolone rearrangement .

But I am not able to find the sterochemistry of the reaction .

Can anyone please tell me the stereochemistry enter image description here

see this:-http://chemistry.stackexchange.com/questions/43858/why-do-we-have-an-alkyl-shift-rather-than-epoxidation-in-a-pinacol-reaction/43859#43859 — Nilay Ghosh, Jun 04 '16 at 06:29
@Martin-マーチン if there is a stereocentre in any other example then what would be the stereochemistry — Koolman, Jun 04 '16 at 06:40
@NilayGhosh in that question about stereochemistry is not mentioned . — Koolman, Jun 04 '16 at 08:54
This is perhaps the best explanation available- https://chemistry.stackexchange.com/questions/64459/ring-contraction-in-pinacol-rearrangement-of-cyclohexane-1-2-diol — Soham, May 22 '18 at 15:55

score 1 · Answer 1 · answered Jun 04 '16 at 11:05

1

The migrating group attacks trans to the leaving OH group:

answered Jun 04 '16 at 11:05

MaxLS

3

This answer implies a concerted mechanism, while the mechanism is usually written stepwise. Can you point us to papers that investigated the mechanism and came to this conclusion? As it stands, your answer seems claiming something without proving it. – Jan Jun 04 '16 at 11:32
Why in second mechanism it becomes five membered ring ? – Koolman Jun 04 '16 at 13:09

1 Answers1