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)

摘要

ROMP of the optical pure monomer of the title compound (1) was performed successfully using the classical WCl6/SnMe4 catalyst. Beside the stereoregularity (sigma(c) = 0.70), the C-13 NMR spectrum of the resulting polymer (P-1) 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 P-1 and for poly(norbornene-2-carboxylic acid) (P-2) resulting from LiOH hydrolysis of P-1. The chirality of P-1 is probably due to the homochiral pantolactonyl side chain and the (S) C-2 backbone carbon. [References: 26]