Reduction of ester and amide with LiAlH4

[duchuy]

Homework Statement

.

Relevant Equations

.

Hi, I am trying to solve number 8. At 7, I have a molecule that contains both an amide and ester function. So when I use LiAlH4, will I reduce both the ester to alcohol and the amide to secondary amine? Or just the ester?
Thank you so much for your help!

 

[chemisttree]

Both are possible. What does APTS stand for in the esterification step?

 

[duchuy]

Both are possible. What does APTS stand for in the esterification step?

I'm not quite sure for the name in english but in french it's acide paratoluène sulfonique. The formula is :
H3C-Ph-HSO3.
I also have a question regarding protecting groups. In a molecule where I have both a RCOOH, or ester and amide group, will I be able to use ethylene glycol or Corey Seeback reaction to protect one group and reduce only the other non protected group? Or protection only works for ketones and aldehydes?
And if I want to specifically reduce say for example the ester and not the amide, is there a more specific reducing agent that only targets one group and not the other like NaBH3CN?

 

[chemisttree]

That’s PTSA in English, or pTs-OH or TsOH.
I don’t know of any protecting groups for amides. I don’t think the Corey Seebach reaction would work with either an ester or an amide. I’ve only seen that done on aldehydes. Ethylene glycol will make a glycol ester if you are careful. Glycol esters are very easily hydrolyzed in my experience. In my hands they hydrolyze during aqueous workup. The only Fisher conditions that I’ve ever used to make them were catalyzed with Amberlite resin which didn’t require aqueous workup.
Lithium borohydride-methanol is fairly reactive to esters and not so much for secondary amides.

 

[duchuy]

That’s PTSA in English, or pTs-OH or TsOH.
I don’t know of any protecting groups for amides. I don’t think the Corey Seebach reaction would work with either an ester or an amide. I’ve only seen that done on aldehydes. Ethylene glycol will make a glycol ester if you are careful. Glycol esters are very easily hydrolyzed in my experience. In my hands they hydrolyze during aqueous workup. The only Fisher conditions that I’ve ever used to make them were catalyzed with Amberlite resin which didn’t require aqueous workup.
Lithium borohydride-methanol is fairly reactive to esters and not so much for secondary amides.

Thank you so much sir! I love your dedication, and I wish you an amazing new year ahead.