Synthesis of 5-deoxy-b-D-Galactofuranosides (5-deoxy-b-L-arabino-Hexofuranosides) starting from D-Galacturonic acid by Photoinduced Electron Transfer (PET) Deoxygenation

MARINO, CARLA; BORDONI, ANDREA V.; LO FIEGO, MARCOS J.; LEDERKREMER, ROSA M. DE

Carbohydrate Chemistry: Proven Synthetic Methods, Volume 3

CRC Press

Año: 2015; p. 45 - 55

We describe here the synthesis of methyl 5-deoxy-B-D-galactofuranoside (5) from D-galacturonic acid (1) through PET deoxygenation. The furanosyl precursor 2, obtained by the resin catalyzed reaction of 1 with methanol is converted to the photoreductible ester 3 and subsequently irradiated to afford the deoxygenated compound 4. Finally, using the NaBH4-I2 system, 5-deoxy glycofuranoside 5 is obtained. The straightforward access to the furanosyl precursor 2, combined with the regioselectivity of the acylation and the easiness of the deoxygenation, significantly shorten the pathway to 5, with respect to previous reports.