反应详情

6.75 ml (0.80 mmol) of 1.6 molar n-butyllithium solution in n-hexane are added dropwise at 0° C. to 2.48 g (9.80 mmol) of 1-ethynyl-4-(trans-4-pentylcyclohexyl)benzene in 25 ml of tetrahydrofuran. After 1 hour, this solution is added dropwise to 0.83 ml of dimethylformamide in 20 ml of tetrahydrofuran, the mixture is stirred at room temperature for 1 hour, acidifed by means of aqueous hydrochloric acid and partitioned between ether and water, and the organic phase is dried and evaporated. Chromatography on silica gel using n-hexane/dichloromethane (1:1) gives 1.75 g of 1-(formylethynyl)-4-(trans-4-pentylcyclohexyl)benzene, ##STR39## which is stirred for 2 hours at room temperature with 1.05 g (6.49 mmol) of diethylaminosulfur trifluoride in 10 ml of dichloromethane. After partitioning between water and dichloromethane, the organic phase is dried over sodium sulfate, evaporated and chromatographed on silica gel using n-heptane, giving 0.89 g of product ##STR40## having the phase sequence

1. custompartitioned between ether and water
2. customthe organic phase is dried
3. customevaporated