Provided are processes for preparing a 3′-deoxypentopyranosyl oligomers with linkers for linking biomolecules. The processes can the steps of: bonding a 4′-protected-3′-deoxypentopyranosyl nucleoside to a solid support by coupling the 2′-OH group with a CPG support or other similar support with an amide linkage; deprotecting the 4′-protected-3′-deoxypentopyranosyl nucleoside at the 4′ position; deprotecting the 4′-protected-3′-deoxypentopyranosyl nucleoside at the 4′ position; and conjugating a linker to the free 4′ position. The resulting product can be conjugated via the linker to a biomolecule. The method can include, prior to addition of the linker, reacting the 4′-OH group of the 4′-protected-3′-deoxypentopyranosyl nucleoside that is linked to the solid support with a 4′-protected-3′-deoxypentopyranosyl nucleoside phosphoramidite in the presence of a coupling reagent, and oxidizing the reaction product. This step can be repeated one or more times to produce an oligomer of desired length.