Catechols can be protected in the presence of phenols as cyclic acetals or ketals or cyclic esters. Esters are also important protective groups for phenols, but are not as stable to hydrolysis as the related alcohol derivatives. Reproduced material should be attributed as follows: Information about reproducing material from RSC articles with different licences By closing this message, you are consenting to our use of cookies. Aryl and alkyl trimethylsilyl ethers can often be cleaved by refluxing in aqueous methanol, an advantage for acid‐ or base‐sensitive substrates.
and you may need to create a new Wiley Online Library account.
; Protected compounds are their methoxymethyl ethers.
For example phenol, C6H5OH gives the protected derivative at room temperature in 81% yield.This reaction is completed in 16 hrs, and zinc chloride etherate catalyses it. Use the link below to share a full-text version of this article with your friends and colleagues.
We now wish to report the use of phenylthiomethyl (PTM) ethers as phenolic protecting groups which may be differentiated from phenolic MTM ethers. is available on our Permission Requests page.
-There are two dimethoxybenzyl (DMB or DMPM) groups (2,4-dimethoxy and 3,4-dimethoxy), both of which can be deprotected under milder conditions than PMB.-PMB trichloroacetimidate (PMB-O(C=NH)CCl 3) provides a way to protect base sensitive compounds under …
This article is part of the themed collections: For reproduction of material from all other RSC journals. Register to receive personalised research and resources by email, An International Journal for Rapid Communication of Synthetic Organic Chemistry, A New Protecting Group for Phenols: Phenylthiomethyl (PTM) Ethers, Department of Chemistry , Virginia Polytechnic Institute and State University Blacksburg , Virginia, 24061, Department of Chemistry , Purdue University West Lafayette , Indiana, 47907, /doi/pdf/10.1080/00397918008061850?needAccess=true. Abstract. Cyclic carbonates have been used to a limited extent only to protect the catechol group in a polyhydroxybenzene.
Licence.
In particular, the protection of alcohols 2,3,4 and phenols 5 as methylthiomethyl (MTM) ethers, and the facile hydrolysis of these ethers back to the parent alcohol or phenol have been reported.
Please check your email for instructions on resetting your password.
This may take some time to load. Material from this article can be used in other publications provided * Presently many of the protecting groups available can require harsh conditions, specialist equipment, expensive or air/moisture-sensitive reagents to install and remove.
To learn about our use of cookies and how you can manage your cookie settings, please see our Cookie Policy.
Licence. Hemithioacetals have previously found utility as protecting groups for alcohols and phenols.
For example, the amino acid tyrosinecould be protected as a benzyl ester on the carboxyl group, a fluorenylmethylenoxy carbamate on the amine group, and a tert-butyl ether on the phenol group. The full text of this article hosted at iucr.org is unavailable due to technical difficulties.
Natural products (e.g., flavonoids, cannabinoids and rotenoids),1 pharmaceuticals (e.g., antiseptics and disinfectants),2 catalysts3 and materials4 all contain phenols in their structures. Phenols are extremely valuable building blocks in the areas of pharmaceuticals, natural products, materials and catalysts.
In particular, the protection of alcohols2,3,4 and phenols5 as methylthiomethyl (MTM) ethers, and the facile hydrolysis of these ethers back to the parent alcohol or phenol have been reported. Department of Chemistry, Durham University, South Road, Durham, UK A protective group (also referred to as "protecting group") is a reversably formed derivative of an existing functional group in a molecule. A protecting group (PG) is a molecular framework that is introduced onto a specific functional group (FG) in a poly-functional molecule to block its reactivity under reaction conditions needed to make modifications elsewhere in the molecule. Registered in England & Wales No. In order to carry out modifications on phenols, the phenolic oxygen is routinely protected to prevent unwanted side reactions.
E-mail: The TFP protecting group is readily cleaved under mild conditions with quantitative conversion to the parent phenol, observed in many cases in less than 1 hour. to access the full features of the site or access our, Department of Chemistry, Durham University, South Road, Durham, UK, Organic & Biomolecular Chemistry HOT articles, Creative Commons Attribution 3.0 Unported
Phenols are a ubiquitous aromatic motif present in a wide range of chemical entities. This article is licensed under a Creative Commons Attribution 3.0 Unported Hemithioacetals have previously found utility as protecting groups for alcohols and phenols. Here we introduce the use of the tetrafluoropyridyl (TFP) group as a general protecting group for phenols.