Hello All,
So for chapter 9 sapling problems, I found that there was a question about an epoxide synthesis but there wasn't mcpba in the options so It took me a lot of attempts to get to the answer but I still cant really get it. Can anyone explain to me how would we get an epoxide using other reagents, what are the most common ones other than mcpba and what is their mechanism.
Thank you
Hint: Williamson Ether Synthesis (we discussed the end of chapter 9)
ReplyDeleteWhich problem were you talking about in particular? The only one that I can think of is #41 because of the epoxide answer options.
ReplyDeleteIf this is the problem that you were thinking of, I also had similar problems with it. I wanted to use the epoxides badly! In the end, I didn't form any epoxides in my synthesis. Instead, I added HBr across the initial alkene (on 2-methyl-1-butene), and then eliminated it off with KOEt to form the more substituted alkene. For the third step, I added Br2 in H2O (this would initially form a cyclic bromonium ion, and the water would back-side attack the more substituted position. Then, another water would deprotonate the oxygen, leaving the alcohol). The water's back-side attack would fulfill the Williamson Ether synthesis, except the Br doesn't detach, as it's still bonded to the other C. This mechanism would form 3-bromo-2-methyl-2-butanol.
As far as forming epoxides, I think the only mechanism that we've been exposed to that can form those so far is the mCPBA mechanism. This, I am not sure about, however.