A new soluble polymer support synthesis of nucleosides is described. The photochemical ring expansion of cyclobutanones in the presence of poly (ethylene glycol)(PEG) results in polymer-supported ribosides. These photoadducts can be cleaved from the polymer under Vorbrüggen coupling conditions with TMS-protected purines and pyrimidines to give ribonucleosides. The method has been extended to include modified PEGs with dendritic ...
[van Tilburg; van der Klein; von Frijtag Drabbe Kuenzel; de Groote; Stannek; Lorenzen; IJzerman Journal of medicinal chemistry, 2001 , vol. 44, # 18 p. 2966 - 2975]