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Chemistry Forums for Students => Organic Chemistry Forum => Topic started by: watizit97 on July 05, 2019, 11:17:21 PM

Title: Rotaxane - Stopper Synthesis
Post by: watizit97 on July 05, 2019, 11:17:21 PM
Hello.

I am a research student currently exploring on how to synthesize water-soluble rotaxanes via Diels-Alder Reaction. But I have a problem what compound I should use as the stopper of the rotaxane.

My criteria for a stopper are :

1) It must be big/bulky (So the γ-cyclodextrin will not leave the rotaxane even after combining the Diene and the Dienophile via Diels-Alder Reaction)
2) It must have a hydroxyl group (This is because both of my diene and dienophile has a carboxylic acid group at end of it, and I would like to combine them with the stopper via esterification)
3) It must be hydrophilic.

I would greatly appreciate if you could attach any kinds of literature to your statement or other alternatives in creating the stopper.

Thank you.
Title: Re: Rotaxane - Stopper Synthesis
Post by: rolnor on July 06, 2019, 10:05:02 AM
Can you be more specific and draw the molecules?
Title: Re: Rotaxane - Stopper Synthesis
Post by: hollytara on July 07, 2019, 12:19:04 AM
Are other sugars big enough?  Glucose?  Sucrose? 
Title: Re: Rotaxane - Stopper Synthesis
Post by: pgk on July 08, 2019, 12:31:31 PM
2-Hydroxymethyl-18-crown-6
https://www.sigmaaldrich.com/catalog/product/aldrich/388440
4′-hydroxymethylbenzo-15-crown-5 obtained from reduction of 4′-Formylbenzo-15-crown-5
https://www.sigmaaldrich.com/catalog/product/aldrich/419974
Additionally, take a look to this article and get ideas about bulky and hydrophilic alcohols with similar structure:
Effect of Stopper Size on Squaraine Rotaxane Stability, Supramolecular Chemistry, 21(1-2), 118-124, (2009)
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2849180/pdf/nihms188720.pdf