August 10, 2022, 06:58:38 AM
Forum Rules: Read This Before Posting


Topic: carbohydrate reaction  (Read 3967 times)

0 Members and 1 Guest are viewing this topic.

Offline a confused chiral girl

  • Full Member
  • ****
  • Posts: 132
  • Mole Snacks: +2/-1
carbohydrate reaction
« on: May 31, 2007, 01:40:02 AM »
Hi everyone  ;D

I am having some problems determining the choice of this reaction. I have the reaction posted below, and there are also 4 choices. I am thinking that the cyclic group would attach to both the O on the anomeric carbon, as well as to the O on the highest stereogenic centre which determines D/L structure.

So I am thinking that there are no cyclic structures adding on to the given structure, but none of the choices fit with my reasoning...

Offline a confused chiral girl

  • Full Member
  • ****
  • Posts: 132
  • Mole Snacks: +2/-1
Re: carbohydrate reaction
« Reply #1 on: May 31, 2007, 01:40:28 AM »
choice 1)

Offline a confused chiral girl

  • Full Member
  • ****
  • Posts: 132
  • Mole Snacks: +2/-1
Re: carbohydrate reaction
« Reply #2 on: May 31, 2007, 01:42:09 AM »
choice 2

Offline a confused chiral girl

  • Full Member
  • ****
  • Posts: 132
  • Mole Snacks: +2/-1
Re: carbohydrate reaction
« Reply #3 on: May 31, 2007, 01:42:48 AM »
choice 3

Offline a confused chiral girl

  • Full Member
  • ****
  • Posts: 132
  • Mole Snacks: +2/-1
Re: carbohydrate reaction
« Reply #4 on: May 31, 2007, 01:43:32 AM »
choice 4

thank you everyone  :)

Offline Custos

  • Full Member
  • ****
  • Posts: 217
  • Mole Snacks: +32/-0
  • Gender: Male
Re: carbohydrate reaction
« Reply #5 on: May 31, 2007, 01:54:45 AM »
The correct answer is choice 2. In the absence of cyclohexanol the sugar can ring close to give the hemiacetal. If you add an alcohol plus acid to a hemiacetal you get an acetal. Look up hemiacetal and acetal in your text and you'll see what I mean.

Sponsored Links