反応 #334856
ord-894b4502453c4d80ab50e89cda2790c7
反応方程式
反応条件
後処理
- 1抽出extracted three times with 100 ml of petroleum ether each time
- 2洗浄The organic phases were washed twice with 100 ml of water each time
- 3乾燥dried over magnesium sulphate
- 4濃縮concentrated
実験手順
A solution of 1.98 g of p-[trans-4-(2,3-dibromopentyl)cyclohexyl]benzonitrile (erythro/threo 66.6:32.8) in 30 ml of glacial acetic acid was treated at room temperature with 2.0 g of zinc powder while gassing with argon and the suspension was stirred at room temperature for 1 hour. The reaction mixture was subsequently poured into 100 ml of water and extracted three times with 100 ml of petroleum ether each time. The organic phases were washed twice with 100 ml of water each time, dried over magnesium sulphate and concentrated. Low-pressure chromatography (0.5 bar) of the yellowish residue (1.16 g) on silver nitrate-coated silica gel with hexane/diethyl ether (vol. 90:10) gave 586 mg (48%) of p-[trans-4-(2E-pentenyl)cyclohexyl]benzonitrile and 171 mg (14%) of p-[trans-4-(2Z-pentenyl)cyclohexyl]benzonitrile as colourless oils. The 2E-isomer has a melting point of 9.6° C. and 16.1° C. (2 modifications) and a virtual clearing point of -67° C.; the 2Z-isomer has a melting point of -7.7° C. and a virtual clearing point of -54° C.