Abstract The synthesis of enantiopure C-12 methoxy-or alkyl-substituted 5, 7, 8, 12b- tetrahydro [4] helicene quinones 16 and 17 and the 7, 8-dihydroaromatic analogues 4 and 5 has been achieved from (SS)-2-(p-tolylsulfinyl)-1, 4-benzoquinone. In the first series, with a structure containing both central and helical chiralities, the R absolute configuration of the stereogenic carbon atom was defined after the asymmetric cycloaddition step, whereas ...
