3-氧代和4-氧代紫罗兰醇乙酸酯的合成路线改进

Improved Synthesis Route of 3-Oxo-α-ionol and 4-Oxo-β-ionol Acetate

以叔丁基过氧化氢(TBHP)和次氯酸钠氧化α-紫罗兰酮,得到关键中间体3-氧代-α-紫罗兰酮(1),同时,进行了条件试验,最佳条件为:在室温条件下,无水乙腈和K2CO3中,n(α-紫罗兰酮):n(TBHP)∶n(NaCl O)为1∶8∶3时,反应得到产物,最佳得率为50.9%。产物再经硼氢化钠选择性还原得氧代紫罗兰醇,经乙酸酐酯化得目标产物3-氧代-α-紫罗兰醇乙酸酯,总收率为32.66%。同时,也进行了4-氧代-β-紫罗兰醇乙酸酯的合成,总收率为31.32%。此方法原料易得,毒性小,成本低,反应操作简便,容易进行。所有中间体及产物的结构经IR,1H NMR,13C NMR和MS证实。

3-Oxo-ionone（1） was prepared by the oxidation of α-ionone with t-butyl hydroperoxide and NaClO in the solvent of acetonitrile and K2CO3.The optimized molar ratio of n（α-ionone）∶n（TBHP）∶n（NaClO） was 1∶8∶3.The yield was 50.9%.It was reduced by NaBH4 and subsequent esterificated by acetic anhydride to give 3-oxo-α-ionol acetate.The total yield was 32.66%.Meanwhile,4-oxo-β-ionol acetate was prepared by the same method.The total yield was 31.32%.This procedure has the advantages of easy to get starting materials,mild reaction conditions and convenient operations.The intermediate and product were characterized by IR、1H NMR、13C NMR and MS.