An unprecedented single-stranded polynorbornene with the pendant group containing benzenedicarboxaldehyde and a long alkyl chain（12） was synthesized by ring-open metathesis polymerization（ROMP） of the corresponding monomer（11）,which was obtained via the esterification of two crucial intermediates,namely,2-hexadecyloxy-5-hydroxymethyl-1,3-benzenedicarboxaldehyde（7,obtained via 6 steps） and 4-（4-aza-tricyclo[5.2.1.0 2.6 ]-dec-8en-4-yl）benzoic acid（10）.The target compound and all the intermediates were characterized by infrared（IR）,1 H NMR and high resolution mass spectroscopy（HRMS） analysis.
After tentative ring-opening cross metathesis （ROCM） of endo-bicyclo[3.2.0]hept-6-en-3-yl 4-bromobenzoate with PhCH = CH2 initiated by （Cy3P）2Cl2Ru = CHPh in CH2Cl2, ring-opening metathesis polymerization （ROMP） of a series of endo-bicyclo[3.2.0]hept-6-en-3-yl benzoates was achieved under the same conditions, furnishing a variety of the corresponding polymers. Then some of them were selected to hydrogenate the C=C double bonds in their backbone with p-tosylhydrazide, affording saturated and thus more flexible polymers. All of these polymers were well characterized by spectroscopic means including GPC, UV-Vis, NMR and IR, based on which the tacticity of these polymers was investigated together with nonlinear optical （electric-field-induced second-harmonic generation, EFISH）） analysis.
