Talk:Corey–Fuchs reaction

How do we know that the reaction happens by a carbene intermediate? I haven't been able to find anything that supports that mechanism. 130.225.0.251 (talk) 19:20, 14 December 2012 (UTC)

If you start from Ar-C(O)D, you get 50% deuterium incorporation for the terminal alkyne. This is consistent with a carbene mechanism; deprotonation/beta-elimination (of LiBr) or Li-Br exchange/beta elimination (of DBr) would both remove the deuterium. I assume the 50% H incorporation is caused by deprotonation of the acidic terminal Alkyne-D by the excess BuLi (they use 2 equiv.). Source: Cato82 (talk) 18:15, 16 February 2016 (UTC)