April 27, 2024, 08:37:46 AM
Forum Rules: Read This Before Posting


Topic: Friedel Crafts acylation  (Read 3426 times)

0 Members and 1 Guest are viewing this topic.

Offline Anna

  • Very New Member
  • *
  • Posts: 1
  • Mole Snacks: +0/-0
  • Gender: Female
Friedel Crafts acylation
« on: February 22, 2009, 08:30:23 PM »
Hello, I need some help with Friedel Crafts acylation.

I am supposed to predict how these two compounds would react under acylation with acetyl chloride. I have done all the other compounds, but I can't find examples in my book for these two.



I also need to know why (for NMR) protons substituted ortho to an acetyl group usually have a greater chemical shift than other protons on the ring.  Would the steric hindrance be greater when ortho and thus shift the signal further from TMS or is it some other reason? 

And also for the two compounds below, how would you tell them apart in NMR?   ???



Any help would be greatly appreciated.    ;D

Offline skido123

  • New Member
  • **
  • Posts: 4
  • Mole Snacks: +0/-0
Re: Friedel Crafts acylation
« Reply #1 on: March 06, 2009, 01:32:17 AM »
for the first one recall electrophilic addition and then removal of proton...It may not be so obvious but draw the assumed hydrogens so you can eliminate a proton...

Offline russellm72

  • Chemist
  • Full Member
  • *
  • Posts: 133
  • Mole Snacks: +10/-7
  • Gender: Male
Re: Friedel Crafts acylation
« Reply #2 on: March 06, 2009, 04:55:56 AM »
Ok. In theory for the NMR question think about the relative coupling constants for 1,3 and 1,4 coupling of the Hydrogens in your compounds.

Ring any bells?

R.

Sponsored Links