Site-Selective Dehydroxy-Chlorination of Secondary Alcohols in Unprotected Glycosides
Ji Zhang1, Niels R M Reintjens1, Jayaraman Dhineshkumar1
1Stratingh Institute for Chemistry, University of Groningen, Groningen 9747 AG, The Netherlands.
Abstract:
To circumvent protecting groups, the site-selective modification of unprotected glycosides is intensively studied. We show that site-selective oxidation, followed by treatment of the corresponding trityl hydrazone with tert-butyl hypochlorite and a H atom donor provides an effective way to introduce a chloride substituent in a variety of mono- and disaccharides. The stereoselectivity can be steered, and a new geminal dichlorination reaction is described as well. This strategy challenges existing methods that lead to overchlorination.
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