摘要：

Optically active bifunctionalized [7]thiaheterohelicene was synthesized using (1R, 2R, 3S, 4S)-endo-3-amino-endo-2-hydroxybornane as a chiral element. The photocyclo-dehydrogenation of 1,2-diarylethylene prepared from benzodithiophenecarboxaldehyde 4 and optically active phosphonium salt 8 gave a 38:62 mixture of the chromatographically separable diastereomers of [7]thiaheterohelicene. The removal of the chiral auxiliary from the diastereomers was readily achieved by thiolysis, and subsequent desilylation and reduction gave new helical ligands possessing C2 symmetry, (P)- and (M)-2,13-bis(hydroxymethyl)dithieno[3,2-e:3′,2′-e′]benzo[1,2-b:4,3-b′]bis[1]benzothiophenes.

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