Synthesis of 7-fluoro-B-homo-19-norcholest-5(10)-en-3.BETA.-ol acetate.
作者:TOSHIO KOBAYASHI、MINORU MAEDA、HIROSHI KOMATSU、MASAHARU KOJIMA
DOI:10.1248/cpb.30.3082
日期:——
The synthesis of 7-fluoro-B-homo-19-norcholest-5 (10)-en-3β-ol acetate (1) was examined by utilizing diethyl (2-chloro-1, 1, 2-trifluoroethyl) amine (FAR), diethylaminosulfur trifluoride (DAST), and/or hexafluoropropene-diethylamine (FPA) as fluorinating agents for cholest-5-en-3β, 19-diol 3-acetate (2), 6β-hydroxymethyl-19-norcholest-5 (10)-en-3β-ol 3-acetate (9), 7β-hydroxy-B-homo-19-norcholest-5 (10)-en-3β-ol 3-acetate (12), and 3β-acetoxy-6β-hydroxy-5β, 19-cyclocholestane (13). The treatment of 2 and 9 with these fluorinating agents gave the 7-fluoro-B-homo-5 (10)-ene (1) in poor yield together with the cyclopropane products, 3β-acetoxy-5β, 6β-methanocholest-1 (10)-ene (3) and 3β-acetoxy-5β, 6β-methanocholest-9-ene (4). When 12 was allowed to react with FAR at -78°C, the required 1 was produced in 43% yield. The most satisfactory result, however, was obtained by the reaction of 13 with FAR at -78°C, which afforded the 7-fluoro-B-homo-5 (10)-ene (1) in 64% yield.
通过使用二乙基(2-氯-1,1,2-三氟乙基)胺(FAR)、二乙基三氟化硫(DAST)和/或六氟丙烯-二乙胺(FPA)作为胆甾-5-烯-3β的氟化剂,研究了 7-氟-B-高-19-去甲胆甾-5(10)-烯-3β-醇乙酸酯(1)的合成、19-二醇 3-乙酸酯(2)、6β-羟甲基-19-去甲胆甾烷-5(10)-烯-3β-醇 3-乙酸酯(9)、7β-羟基-B-高-19-去甲胆甾烷-5(10)-烯-3β-醇 3-乙酸酯(12)和 3β-乙酰氧基-6β-羟基-5β,19-环胆甾烷(13)的氟化剂。用这些氟化剂处理 2 和 9,可以得到产率较低的 7-氟-B-高-5 (10)-烯 (1),以及环丙烷产物 3β-乙酰氧基-5β,6β-甲基胆甾烷-1 (10)-烯 (3) 和 3β-乙酰氧基-5β,6β-甲基胆甾烷-9-烯 (4)。当 12 与 FAR 在-78°C 下反应时,生成了所需的 1,收率为 43%。然而,最令人满意的结果是 13 与 FAR 在-78°C 下反应,得到了 7-氟-B-高-5 (10)-烯 (1),收率为 64%。