Abstract
The use of the base labile 2-(p-nitrophenyl)-ethoxycarbonyl (NPEOC), 2-(2,4-dinitrophenyl)-ethoxycarbonyl (DNPEOC) and 2-cyanoethoxy-carbonyl (CEOC) group for hydroxyl protection of the sugar moiety in ribo-nucleosides and deoxyribonucleosides are described and discussed.