Synthesis of a Chiral Helical Molecular Template Based on trans-5,6,6a,7,8,12b-Hexahydro-1,12-dimethylbenzo[c]phenanthrene- 5,8-dione.

Reduction of trans-5,5,6a,7,8,12b-hexahydro-1,12-dimethylbenzo[c]phenanthrene-5,8-dione (1, R(1) = R(4) = H, R(2) = R(3) = CH(3)) with lithium aluminum hydride yielded stereoselectively (5RS,8RS)-trans-5,6,6a,7,8,12b-hexahydro-1,12-dimethylbenzo[c]phenanthrene-5,8-diols 2, X = H. These diols proved to be configurationally stable chiral molecular templates capable of straightforward modification by attachment of molecular elements of different length and kind. The structures of the diacetate 2, X = COCH(3), and (5R,8R)-(-)-trans-5,6,6a,7,8,12b-hexahydro-1,12-dimethylbenzo[c]phenanthrene-5,8-diyl di-p-bromobenzoate (2a, X = p-BrC(6)H(4)CO), as well as the absolute configuration of the latter were obtained by X-ray crystallography.