Sulfuric Acid → GlyTouCan:G62599KV

Treatment of unprotected 2-deoxy-2-fluoro-L-arabinopyranose with one equivalent of either sulfuric or hydrochloric acid at room temperature failed to give the desired furanoside. Only unreacted starting material was detected. Using nine equivalents of hydrochloric acid gave the desired product 2-deoxy-2-fluoro-L-arabinofuranose, which was contaminated with starting material (2:1 ratio). The best result, so far, was achieved by refluxing 2-deoxy-2-fluoro-L-arabinopyranose with 1 equivalent of sulfuric acid in dry methanol. After 6 hours all of the starting material had disappeared affording 2-deoxy-2-fluoro-L-arabinofuranose as an oil in 80% yield. 1H-, 13C- and 19F-NMR indicated a 3:1 α:β mixture of anomers, with some minor impurities. L-ribo- and L-arabinopyranoside as well as L-ribofuranoside are the possible side products. The D-isomer of 2-deoxy-2-fluoro-L-arabinofuranose was previously made by two different groups, but in less efficient ways (Wright, J. A.; Taylor, N. F.; Fox, J. J. J. Org. Chem 1969, 34, 2632. and Wysocki, R. J.; Siddiqui, M. A.; Barchi, J. J.; Driscoll, J. S.; Marquez, V. E. Synthesis 1991, 1005).

1. customThe best result

ORD record

ord-f4e32b43de87429ab8068aa016af369a

Source dataset

uspto-grants-2007_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07291726B2