scheme 1 illustrated below 1 silylation of the 5 u2032 dimethoxytritylated and appropriately protected nucleosides using 1 3 dichloro 1 1 3 3 tetraisopropyl disiloxane in dry pyridine with addition of imidazol 2 reacting of the formed monochloroderivative 3 with an diol e g tetraethylene glycol to obtain derivative 4 3 introduction of phosphoramidite function to the free hydroxyl group located at the end of the 3 u2032 linker according to the invention the homobifunctional readily available reagent 1 3 dichloro 1 1 3 3 tetraisopropyl disiloxane 2 scheme 1 was used in other words the reagent used in the present invention has two reactive functions which enables high and controllable substitution a disiloxyl residue was applied as a stable linker function between a nucleoside and a solid support the reactive intermediates 3 or 5 were synthesized in one or three steps respectively according to scheme 1 above no attempts were made to isolate intermediate 3 therefore silylation of appropriately protected nucleosides 1 were performed using only a slight excess of 2 the addition of an excess of an 13 atoms long chain diol tetraethyleneglycol resulted in the formation of an unsymmetrical disiloxyl derivative 4 used subsequently for the synthesis of phosphoroamidite 5 the invention requires a support functionalized with hydroxyl groups linked to the support through nonhydrolyzable bonds mono r hydroxyalkyl derivatized polystyrene particles from pharmacia was used without modifications derivatization of cpg proceeded according to scheme 2 below a refluxing of 6 aminohexanoic acid in dry.