We also acknowledge previous National Science Foundation support under grant numbers 1246120, 1525057, and 1413739. Videos in Alcohol Protecting Groups. Missed the LibreFest? Removing the protecting group and reforming the original functional group. Protecting Groups for Alcohols- Ether protection (Alcohol to ether) • 2-Methoxyethoxymethyl ether (MEM) • Selective protection is possible • Can be incorporated at relatively weak basic conditions (3° amine) but needs • relatively strong acid (TFA) to remove • Stable in basic conditions • The reagent, MEMCl, is considered carcinogenic Well, scientists determined, you know what, alcohols are messing up a lot of different reactions, so if we can figure out a way to get rid of the alcohol for a few minutes, then run the rest of the reaction and then regenerate the alcohol, that would be really helpful. 15 - Analytical Techniques: IR, NMR, Mass Spect, Ch. Previous Section Ether Cleavage. Legal. 20 - Carboxylic Acid Derivatives: NAS, Ch.
How can we guarantee that a reaction won’t take place at the alcohol? All of these reactions, except one, will require some sort of protecting group. Silyl ethers are a group of chemical compounds which contain a silicon atom covalently bonded to an alkoxy group.
The reason for that is that you're supposed to be able to take the molecule off after the reaction is complete. 1.
So if I do want this reaction to happen, is there any way to make it only react with the alkyl halide and not the alcohol? Let's look at this reagent. Well, in this case, what I'm trying to do is as you can see, my end product, I'm trying to make this alkynide perform a substitution reaction on the alkyl halide. When situations like this occurs chemists circumvent the problem by protecting the interfering functional group. Let's go ahead and look at this reaction. Protecting Groups in Organic Synthesis-1 Ready Protecting groups are a sad fact of synthetic chemistry They are usually needed, but rarely desired Many syntheses have stalled because of trouble putting on or removing protecting groups 4 basic questions to address when choosing a P.G. (Note that you may not actually know a good protecting group for each reaction.) Looks like you’ve clipped this slide to already. Additional Problems. THEIR DEPROTECTION I know that sounds complicated, but basically what we're going to try to do is we're going to try to shield vulnerable functional groups from certain types of strong reagents.