Studies on the chemical constituents of rutaceous plants. L. Development of a versatile method for the synthesis of antitumor-active benzo(c)phenanthridine alkaloids. 2. Preparation of 2-aryl-1-tetralone derivatives.
作者:HISASHI ISHII、ERI KAWANABE、KENICHI HARADA、TAKEO DEUSHI、ETSUKO UEDA、TOSHIKO WATANABE、YUHICHIRO ICHIKAWA、MITSUGI SAKAMOTO、TOSHIAKI ISHIDA、TSUTOMU TAKAHASHI、KEIKO NAKAJIMA、TSUTOMU ISHIKAWA
DOI:10.1248/cpb.31.3039
日期:——
The synthetic pathway from 2, 4-bisaryl-4-oxobutyramide (3) to 2-aryl-1-tetralone (4), which is the key intermediate in the Robinson synthesis of antitumor-active benzo [c] phenanthridine alkaloids was improved. Treatment of the model keto-amide (3a) under the reported basic conditions gave a γ-keto-α, β-unsaturated acid (9) and degradation products. Reduction of the 2, 4-bisaryl-4-oxobutyramide (3) with sodium borohydride gave 2, 4-bisaryl-4-hydroxybutyramide (16), which could easily be hydrogenolyzed to give 2, 4-bisarylbutyramide (15). However, this transformation also tended to give a γ-lactam derivative (17), unfortunately. We succeeded in the direct hydrogenolysis of the 2, 4-bisaryl-4-oxobutyramide (3) to the 2, 4-bisarylbutyramide (15), which could be hydrolyzed to the corresponding acid (5) without difficulty. The direct hydrolysis of the 2, 4-bisaryl-4-oxobutyronitrile (2) to the 2, 4-bisaryl-4-oxobutyric acid (6) as reported by Cheng et al. was also examined. Ten 2-aryl-1-tetralones (4) required as starting materials for syntheses of various benzo [c] phenanthridine alkaloids were prepared.
从 2,4-二芳基-4-氧代丁酰胺(3)到 2-芳基-1-四氢萘酮(4)的合成途径得到了改进,而 2-芳基-1-四氢萘酮是罗宾逊合成具有抗肿瘤活性的苯并[c]菲啶生物碱的关键中间体。在报告的碱性条件下处理模型酮酰胺(3a),可得到γ-酮-α,β-不饱和酸(9)和降解产物。用硼氢化钠还原 2,4-双芳基-4-氧代丁酰胺(3),可得到 2,4-双芳基-4-羟基丁酰胺(16),很容易将其氢解,得到 2,4-双芳基丁酰胺(15)。然而,令人遗憾的是,这种转化也倾向于得到一种 γ-内酰胺衍生物(17)。我们成功地将 2,4-双芳基-4-氧代丁酰胺 (3) 直接氢解为 2,4-双芳基丁酰胺 (15),后者可以顺利地水解为相应的酸 (5)。此外,还研究了 Cheng 等人报告的 2,4-二芳基-4-氧代丁腈(2)直接水解为 2,4-二芳基-4-氧代丁酸(6)的情况。制备了十种 2-芳基-1-四氢萘酮(4),作为合成各种苯并[c]菲啶生物碱的起始原料。