SULFUR-CONTAINING OPTICALLY-ACTIVE POLYMERS .5. SYNTHESIS AND CHIROPTICAL PROPERTIES OF OPTICALLY-ACTIVE POLY(GAMMA-KETOSULFIDE)S PREPARED BY POLYADDITION OF 1,3-DIMERCAPTOBENZENE TO 4,4-DIMETHYL-2,5-CYCLOHEXADIEN-1-ONE OR TO TRANS, TRANS-2,5-HEPTADIEN-3-ONE IN THE PRESENCE OF CHIRAL AMINES

Optically active poly(gamma-ketosulfide)s having the asymmetric center s disposed along the main chain have been prepared by step polyadditio n of 1,3-dimercaptobenzene to 4,4-dimethyl-2,5-cyclohexadiene-1-one, o r to trans, trans-2,5-heptadiene-3-one, in the presence of catalytic a mounts of chiral amines. The extent of asymmetric induction on the res ulting polymeric product is found to be higher when the alicyclic keto ne reagent is employed and is enhanced by lowering the catalyst concen tration. The comparison of stereochemical features and chiroptical pro perties of appropriate low molecular weight analogues with those of th e polymeric derivatives indicates that a comparable asymmetric inducti on occurs in polymers and model compounds, and that the former systems do not display appreciable evidence of ordered secondary structures, in agreement with a low stereoregularity degree along the macromolecul ar backbone. (C) 1996 John Wiley & Sons, Inc.