Ring-opening metathesis polymerization of 2-(S)-(-)-endo-D-pantolacton-O-yl norbornene-2-carboxylate using a classical ROMP catalyst. Synthesis and characterization of optically active poly(norbornene-2-carboxylic acid)

ROMP of the optical pure monomer of the title compound (1) was performed successfully using the classical WCl6/SnMe4 catalyst. Beside the stereoregularity (σc = 0.70), the 13C NMR spectrum of the resulting polymer (P1) evidenced a noticeable directional regularity (B = (HT + TH)/(HH + TT) = 1.6) which can be due to sterically induced regiospecificity in the norbornenyl ring opening during propagation. Significant optical activities were observed for P1 and for poly(norbornene-2-carboxylic acid) (P2) resulting from LiOH hydrolysis of P1 . The chirality of P1 is probably due to the homochiral pantolactonyl side chain and the (S) C2 backbone carbon.