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Chemistry Forums for Students => Organic Chemistry Forum => Organic Chemistry Forum for Graduate Students and Professionals => Topic started by: LeoLeoBest on August 17, 2020, 10:01:14 PM

Title: Synthetic method for PETG derivatives
Post by: LeoLeoBest on August 17, 2020, 10:01:14 PM
I want to introduce a functional group (e.g. Carboxyl, amine) to the benzene ring of PETG (2-phenylethyl β-D-thiogalactoside), does anyone have some suggestions on the synthetic route? In addition, the functional groups should be tethered to the benzene ring with a rigid linker, the substitution reaction is preferred at an orthogonal position. Thanks!
Title: Re: Synthetic method for PETG derivatives
Post by: billnotgatez on August 17, 2020, 11:05:31 PM
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Title: Re: Synthetic method for PETG derivatives
Post by: AWK on August 18, 2020, 01:53:58 AM
Rather no chance of functionalization of the phenyl group in the glycoside. Think about synthesizing the appropriate aglycone and forming a glycosidic bond in the last steps of the synthesis.
Title: Re: Synthetic method for PETG derivatives
Post by: LeoLeoBest on August 18, 2020, 05:59:15 AM
I was actually considering using Friedel-Crafts Acylation perhaps with succinic anhydride, it is possible?
Title: Re: Synthetic method for PETG derivatives
Post by: LeoLeoBest on August 18, 2020, 06:00:38 AM
Rather no chance of functionalization of the phenyl group in the glycoside. Think about synthesizing the appropriate aglycone and forming a glycosidic bond in the last steps of the synthesis.
How about using Friedel-Crafts Acylation with Succinic anhydride?
Title: Re: Synthetic method for PETG derivatives
Post by: kriggy on August 18, 2020, 07:00:25 AM
I was actually considering using Friedel-Crafts Acylation perhaps with succinic anhydride, it is possible?

Everything is possible but I would expect some sugar side reaction under the acidic conditions.
Title: Re: Synthetic method for PETG derivatives
Post by: AWK on August 18, 2020, 07:29:15 AM
PETG is a rather expensive reagent and not very stable.
Succinoyl group, being a bulky group, usually avoids the ortho position.
I wish you success, although I don't believe in it.
Title: Re: Synthetic method for PETG derivatives
Post by: rolnor on August 18, 2020, 09:38:46 AM
It seems very bad mix a glycoside with AlCl3 and succinoylchloride, it will be a complete mess. All the OH-groups will be acylated and the succinoylchloride can form cyclic esters or dimer-polymer-esters. You need to se how PETg is synthesized and go in early with a good substituent on the aromatic ring.
Title: Re: Synthetic method for PETG derivatives
Post by: Babcock_Hall on August 18, 2020, 02:18:19 PM
Echoing Rolnor, I would worry that the hydroxyl groups will react with reagents used to modify the ring.  I think that AWK has the right approach:  Modify the aromatic ring first, then attach it to glucose.