Search

© 2015 American Chemical Society. This is an open access article published under a Creative Commons Attribution (CC-BY) License, which permits unrestricted use, distribution and reproduction in any medium, provided the author and source are cited., 2-Deoxy-2-fluoroglycosyl iodides are privileged glycosyl donors for the stereoselective preparation of 1-Nu-β-fluorosugars, which are useful reagents for chemical site-selective protein glycosylation. Ready access to such β-fluorosugars enables the mild and efficient construction of well-defined fluoroglycoproteins., We thank the European Commission (Marie Curie CIG, O.B. and G.J.L.B.), MICINN, Spain (Juan de la Cierva Fellowship, O.B.), MINECO, Spain (CTQ2011-22872BQU), and General- itat de Catalunya (M.S.) for generous financial support. We also thank Mr. Adrià Cardona-Benages (URV) for technical assistance. G.J.L.B. thanks the Royal Society (University Research Fellowship), Fundação para a Ciência a Tecnologia, Portugal (FCT Investigator), and the EPSRC for funding.

We have reinvestigated the reaction of α-pyranosides-2-uloses 13, 14, 19 and 24 with DAST and shown that the 1,2-difluorinated compounds 17, 18 and 25 are produced by a ring-contraction reaction. The reaction of 18 with benzyl alcohol gives the tri-benzyl derivative 26 or compound 27, depending on the reaction conditions. Treating 17 with 2-naphthol produced the spiranic compounds 29–31. The reaction of 17 with bis(trimethylsilyl)uracil produced the mononucleoside 28, which preserves the fluorine atom in the more substituted carbon.