Sulfuric Acid → (-)-cis-1,2-Dimethoxy-4-(2-aminocyclohexyl)benzene

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Reaction Steps

Specific rotation: [ α ] D 20 = - 58.5 ° ⁢   ⁢ C ⁢   ⁢ ( c = 1 , ethanol ) . C1. (+/−)-cis-1,2-Dimethoxy-4-(2-nitrocyclohex-4-enyl)benzene 10.0 g of (+/−)-trans-1,2-dimethoxy-4-(2-nitrocyclohex-4-enyl)benzene and 20.0 g of potassium hydroxide are dissolved in 150 ml of ethanol and 35 ml of dimethylformamide. A solution of 17.5 ml of conc. sulfuric acid in 60 ml of ethanol is then added dropwise such that the internal temperature does not exceed 4° C. After stirring for 1 h, the mixture is added to 1 l of ice water, the precipitate is filtered off with suction, washed with water and dried, and the crude product is recrystallized from ethanol. 8.6 g of the title compound of m. p. 82.5-84° C. are obtained. C2. (+/−)-cis-1,2-Dimethoxy-4-(2-nitrocyclohexyl)benzene

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