In the synthesis of a library of N-alkyl-3-aza-8-oxabi-cyclo[3.2.1]octane-6,7-dimethanol derivatives, prepared from an 7-oxabicyclo[2.2.1]hept-2-ene-5,6-dimethanol derivative via ring opening metathesis polymerisation using Cl-2(Cy3P)(2)Ru=CHPh, selective alkylation, ozonolytic scission of the polymer backbone and reductive alkylation, purification was facilitated by the differential solubility of the polymer intermediates.