【作者】 张琪；

【导师】 周向东；

【作者基本信息】 第三军医大学 ， 药物化学， 2009， 硕士

【摘要】 来源于海洋生物及其代谢产物的多羟基甾醇类化合物通常具有独特的结构和生物活性,对于新药研发具有重要的研究价值。本论文的目的是建立以胆烷酸甲酯为原料,两步法高效构建24-高-?24(28)-甾体侧链的方法,并在此方法学建立的基础上,原子简洁的,高效合成了海洋天然产物24-高-?24(28)-胆甾烷-3β,5α,6β-三醇和以?24(28)-甾体化合物为底物,用Sharpless不对称双羟化反应,不对称合成24S,28和24R,28-二羟基甾体化合物。首先,以不同结构的胆烷酸甲酯为底物,建立了常温下经过三乙胺络合和微量TMEDA辅助的选择性异丙基化格氏反应,再经Wittig烯化反应,以70%~85%的收率两步高效构建24-高-?24(28)-胆甾化合物的方法。第二,以猪去氧胆酸甲酯为原料,?5-3β-四氢吡喃氧基胆甾-24-酮为关键中间体,异丙基化格氏反应为关键步骤,经7步反应,以53%的总收率原子简洁的、高效合成海洋天然产物24-高-?24(28)-胆甾烷-3β,5α,6β-三醇。第三,以不同结构的24-高-?24(28)-胆甾化合物为底物,通过改良的Sharpless不对称双羟化反应,合成了24S,28和24R,28-二羟基甾体化合物。本论文工作的明显特征是:经过三乙胺络合和微量TMEDA辅助的选择性异丙基化格氏反应和Wittig烯化反应,以70%~85%的收率两步法高效构建24-高-?24(28)-胆甾化合物,减少了三乙胺的用量,将反应温度由原来的低温反应提高到室温,并在此方法学建立的基础上,合成24-高-?24(28)-胆甾烷-3β,5α,6β-三醇和24S,28和24R,28-二羟基甾体化合物。更多还原

【Abstract】 Polyhydroxysterols from natural marine products plays important roles in new-drug discovery and development due to their novel structure and bioactivities. The aim of this dissertation is to concisely and highly efficient construct 24-homo-?24(28)-steroidal sidechain from cholanate acid and synthesize the natural marine product--24-homo-?24(28)-cholesten- 3β,5α,6β-triol from hyodeoxycholic and asymmetric synthesis of 24R,28-dihydroxysteroids and 24S,28-dihydroxysteroids by Sharpless catalytic asymmetric dihydroxylation using 24-homo-?24(28)-steroids as substrates.First of all, 24-homo-?24(28)-steroids were synthesized in a yield of 70%~85% by Et3N-chelated TMEDA-assisted isopropylation from a variety of methyl cholanate and Wittig olefination.Secondly, the natural marine product--24-homo-?24(28)-cholestan-3β,5α,6β-triol was synthesized in 7 steps with a total yield of 53% using methyl hyodeoxycholanate as the starting material, 3β-(tetrahy-dropyran-2-yloxy)-cholest-5-ene-24-one as the key intermediate and Grignard isopropylation as the key step.Finally, 24R,28-dihydroxysteroids 24S,28-dihydroxysteroids was synthesized by using improved Sharpless catalytic asymmetric dihydroxylation.In summary, 24-homo-?24(28)-steroids were synthesized in two steps from methyl cholanate utilizing the intact sidechain of methyl cholanate. In the base of it, 24- homo-?24(28)- cholesten-3β,5α,6β-triol and 24R,28-dihydroxysteroids 24S,28-dihydroxysteroids were synthesized concisely and efficiently.更多还原