A stereospecific synthesis of l-deoxyribose, l-ribose and l-ribosides

Using an inexpensive d -galactose from the chiral pool, l -deoxyribose, l -ribose and their derivatives were synthesized via mild reaction conditions. During the synthesis of l -deoxyribose, the key deoxygenation of the 2-hydroxy group of 3,5-O-dibenzyl-methyl- l -arabinofuranoside was performed by reduction of the corresponding triflate with tetrabutylammonium borohydride in high yield. During the synthesis of l -ribose, the key step of inversion of the 2-hydroxy group in the same substrate was carried out by intramolecular SN2 tandem reaction. Then the l -ribosyl donors were submitted to glycosidations according to Vorbruggen's conditions to give l -ribosides ( l -uridine, l -5-fluorouridine, l -iodouridine, l -thymidine, l -puridine, l -adenosine and l -guanosine) in excellent yields.