Hydrochloric 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. customat room temperature
2. customto give the desired furanoside

ORD record

ord-1dbdafa445874cfaab98cd3e6c500787

Source dataset

uspto-grants-2005_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06870048B2