Towards Configurationally Stable [4] Helicenes: Enantioselective Synthesis of 12??Substituted 7, 8??Dihydro [4] helicene Quinones

…, S García??Cerrada, MJ Sanz??Cuesta…

Index: Carreno, M. Carmen; Enriquez, Alvaro; Garcia-Cerrada, Susana; Sanz-Cuesta, M. Jesus; Urbano, Antonio; Maseras, Feliu; Nonell-Canals, Alfons Chemistry - A European Journal, 2008 , vol. 14, # 2 p. 603 - 620

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Citation Number: 47

Abstract

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 ...