I do not undertsand these two questions. Thanks for any help in advance! Post-la
ID: 560784 • Letter: I
Question
I do not undertsand these two questions. Thanks for any help in advance!
Post-lab Question #1 : The pKa of ethyl acetoacetate is 10.7. What is the Keq for the reaction shown below? (2 points) + HO - OCH2CH3 OCH2CH3 Post-lab Question #2: Why is it important that the alcohol solvent consist mostly of ethanol? Explain why it would not be a good idea to perform this reaction in 95% methanol. You should provide any appropriate mechanisms to support your answer. (3 points) Post-lab Question #3: In the reading in the lab manual, the original procedure by Robinson is described. Why was important for Robinson to add a lithium enolate to the enone that he used? That is, what would be the concern with mixing the ketone and enone together and then adding base? (3 points)Explanation / Answer
Q1
pKa of ethyl acetoacetate 10.7; meaning it acts as an acid, donates H+, then Ka
OH- + H+ <-> H2O, this is Kw inverted, that is 1/Kw
Ktotal = Ka*1/Kw = Ka/Kw = (10^-10.7)/(10^-14) = 1995.26
Q2
ethanol is protic solvent, is has H+ presnet in the OH group, we need this in order for OH- and H2O to fform the proton transfer
methanol is mcuh more reactive, it will likely react or bond with the newly formed ion
Q3
is we add the base afterwards, the base will destroy the enone's conjguated system, therefore, will not form the final product
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.