Destroyer 2 questions on orgo, please help!

[Lazerous]

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1) OK, questions #'s 8, 11, and 15 all involve chlorination. Yet in 8 we abstracted all alpha-hydrogen's while in 11 and 15 we directed the Cl atom into their appropriate position based on the directors. My question is, how am I supposed to know whether to abstract H's or direct the chlorine to an o-p or meta position? Or are these two different reactions? If so then what type of reaction would #8 be?

2) I've never seen this rxn before, and only upon typing up this post did I realize it is somewhat similar to #8, si it? Can someone explain it, please.

 

[osimsDDS]

I believe you have to watch out for the reagents used...you see how in #8 you have Cl2/H3O+ in excess...that means that you will deprotonate the acidic hydrogens and add on Chlorines in each position and because its in excess you add until no more protons can be taken off...

Now #15 you have FeCl3, whenever you see that its going to be an electrophilic aromatic substitution where you add the Cl to the ring depending on the activators/deactivators...in this case you have an activator that takes presence over the deactivator (carbonyl group) and therefore it will be ortho to the -NH group...

Rule of thumb:
Whenever you see FeCl3/FeBr3/AlCl3 assume you will be adding to the ring via activators/deactivators

Whenever you have SOCl2/PBr3/PCl5 assume you will be doing substitution of an alochol to form an acyl halid of some sort...

 

[Lazerous]

I believe you have to watch out for the reagents used...you see how in #8 you have Cl2/H3O+ in excess...that means that you will deprotonate the acidic hydrogens and add on Chlorines in each position and because its in excess you add until no more protons can be taken off...

Now #15 you have FeCl3, whenever you see that its going to be an electrophilic aromatic substitution where you add the Cl to the ring depending on the activators/deactivators...in this case you have an activator that takes presence over the deactivator (carbonyl group) and therefore it will be ortho to the -NH group...

Rule of thumb:
Whenever you see FeCl3/FeBr3/AlCl3 assume you will be adding to the ring via activators/deactivators

Whenever you have SOCl2/PBr3/PCl5 assume you will be doing substitution of an alochol to form an acyl halid of some sort...

Thanks for the explanation, it makes sense. I never knew this but I guess the hydrogen's alpha to a carbonyl are acidic?

Nice rules of thumb as well 👍

Also for my 2nd question I forgot to mention I was talking about #31, can you please explain that to me as well. I'm assuming it does the same thing as #8 except how am I supposed to know DCl is an acid, unless it is supposed to be something like HCL...

 

[osimsDDS]

yea so hydrogens alpha to a carbonyl are called "acidic" because the oxygen pulls alot of electrons from the carbon and the adjacent carbons so therefore the hydrogens alpha to the carbonyl can dissociate or get pulled off easily and therefore are termed acidic...

Yea 31 is weird i never understood that...maybe someone can explain that one to us

 

[jdent]

Its an alpha substitution just sub all alpha H's with D.