Optically active oligo- and polyamides from optically active spiro[3.3] heptane-2,6-dicarboxylic acid

Optically active (R)-spiro[3.3]heptane-2,6-dicarboxylic acid was obtained b y optical resolution with brucine. Its optical purity was confirmed by HPLC analysis on optically active stationary phase. The specific optical rotati ons of model compounds having one and two spiran units increased with incre asing the number of spiran unit in sulfuric acid solution. On the contrary, the specific optical rotations showed opposite sign in organic solvents, s uch as N,N-dimethylformamide and N,N-dimethylacetamide, and the absolute va lues decreased with increasing the number of spiran unit. Polycondensation of (R)-spiro[3.3]heptane-2,6-dicarboxylic acid chloride and 3,3'-dimethoxyb enzidine gave a polymer soluble in common organic polar solvents. This poly mer showed a large positive Cotton effect.