Highly diastereoselective synthesis of novel polymers via tandem Diels-Alder-ene reactions

Cis-9,10-dihydro-9, 10-ethanoanthracene-11-12-dicarboxylic acid anhydride ( 1) was converted into its amic acid derivative by reaction with L-leucine. The cyclization reaction was carried out in situ using triethylamine to giv e the succinic imide-acid derivative (2). Compound (2) was converted to the acid chloride (3) by reaction with thionyl chloride. The reaction of acid chloride (3) with isoeugenol (4) was carried out in chloroform and a novel optically active isoeugenol ester derivative (5) was obtained in high yield . 4-Phenyl-1,2,4-triazoline-3,5-dione (PhTD) (6) was allowed to react with compound (5). The reaction is very fast and gives only one diastereoisomer of (7) via Diels-Alder and ene pathways in quantitative yield. Compound (7) was characterized by H-1 NMR, IR, specific rotation and elemental analysis , and was used as a model for the polymerization reactions. The polymerizat ion reactions of compound (5) with bis-triazolinediones (8), (9) were perfo rmed in N,N-dimethylacetamide (DMAc) at room temperature. The reactions are exothermic and fast, and give novel optically active polymers. Some physic al properties and structural characterizations of these new polymers have b een studied, and are reported. (C) 1999 Society of Chemical Industry.