What a clear explanation. Thank you very much

Thank you very much

What about the size of the triphenyl phosphonium group? Wouldn't if often be larger than the R1 group?

@mevansthechemist

5 жыл бұрын

This is certainly true, and it's something I didn't consider until after making the video. However, note that even if the triphenyl phosphonium group is anti to R2 in the transition state-probably more reasonable than what I drew in many cases-this would place R1 and R2 gauche, and less rotation would be needed for P-O bonding. As a result, R1 and R2 would still end up cis! Only the transition state in which hydrogen is anti to R2 leads to the trans product.

@mevansthechemist

5 жыл бұрын

Great question, by the way!

@dlvivlviv

4 жыл бұрын

@@mevansthechemist I have a question, why do we assume that the phosphorus ylide is in R conformation? S conformation would be energetically preferred, the R1 group would end up in gauche position only towards R2.