Alkoxyl Radical Fragmentation Reaction

The alkoxyl radical fragmentation (ARF) reaction1 is a research line that has been developed by this laboratory. In previous studies2 by our research group, we have described that starting from carbohydrates (a) by β-fragmentation of alkoxyl radicals (FRA), generated by reaction of carbohydrate anomeric alcohol with hypervalent iodine reagents (DIB) in the presence of iodine, iodoformates (b) are obtained with a carbon atom less than the starting carbohydrate.

d.fig1

Versatile chiral synthons as iodo azides, iodo sulfones, iodo phosphonates and iodo phophine oxides have been prepared using this methodology as key step. A subsequent basic dehydroiodination afforded the corresponding vinyl derivatives.

Synthesis of 1-Phospha-Sugars by ARF of Carbohydrates

1-Phospha-sugars are analogs in which the anomeric carbon atom is replaced by a phosphorus atom.

d.fig2

Phostones and phostines have received continued attention in the literature mainly due they are potential inhibitors of glycosidases and have shown anticancer activities. Since there are few syntheses of these compounds we propose to obtain them using as a key step the ARF of carbohydrates. So using short and simple strategies would synthesize phostones, phostines and 2,2-difluoro-1-phospha sugars.

Suárez, E.; Rodríguez, M. S. en Radicals in Organic Synthesis; Renaud, P.; Sibi, M. P., Eds.; Wiley–VCH: Weinheim, 2001; Vol. 2, pag. 440. a) Hernández-Guerra, D.; Rodríguez, M. S.; Suárez, E. Eur. J. Org. Chem. 2014, 5033. b) Hernández-Guerra, D.; Rodríguez, M. S.; Suárez, E. Org. Lett. 2013, 15, 250. c) Alonso Cruz, C. R.; Kennedy, A. R.; Rodríguez, M. S.; Suárez, E. Tetrahedron Lett. 2007, 48, 7207. d) Alonso-Cruz, C. R.; León, E. I.; Ortiz-López, J.; Rodríguez, M. S.; Suárez, E. Tetrahedron Lett. 2005, 46, 5265.