Next, given the clear thermodynamics at play in the reaction, we turned our attention to the effect of reaction time on the equilibriums as we had explored in our previous report. For the non-chiral approach using lithium pyrrolidide, lithiation time did not seem to have a significant impact on the reaction outcome and no major side reactions were observed at lower temperatures. Deprotonation of 1 is usually very fast (< 15 min), and when lithiation was monitored for 90 min, the mass balance was always higher than 95 % for all time points. The same observation held true for the chiral lithium amide 11. With regard to the 1,2-addition, it was found that the reaction time is critical to avoid the undesired retro-addition and ketone 2 enolization. For our non-asymmetric approach, the longer the reaction was carried out (> 30 min after completion of ketone 2 addition), the more the reaction was dominated by the thermodynamically driven enolization, leading to the deterioration of the overall yield.