8-Cyclonucleosides derived from purine bases can be prepared by a number of reactions starting from appropriately modified nucleosides or their 8-substituted (most frequently bromo, hydroxy and sulfanyl) derivatives. The 8-cyclonucleosides are compounds suitable for studying configurations and conformations of purine nucleosides, also useful as intermediates in the synthesis of many biologically interesting compounds. Although the interest in 8-cyclonucleosides culminated in the sixties and seventies, many papers return to them at present and utilize them in various syntheses.