Studies on Aconitum Species. XV. Deoxygenation Reaction of Aconitine Type Alkaloids.
作者:Takao MORI、Mitsuo MURAYAMA、Hideo BANDO、Norio KAWAHARA
DOI:10.1248/cpb.39.2803
日期:——
Mesaconitine (1) in tetrahydrofuran reacted with sodium hydride, a catalytic amount of imidazole, carbon disulfide and methyl iodide at room temperature to give the di-O-(S-methyl)thiocarbonate (5). The reductive cleavage of 5 with tri-n-butyltin hydride gave isodelphinine (3) in a high yield of 83%. The exact same reactions of aconitine (2) and jesaconitine (6) gave penduline (4) and 3, 13-dideoxyjesaconitine (7) in 85 and 86% yields, respectively. The same reactions in diethylether, in place of tetrahydrofuran, gave the 3-deoxy compounds, hypaconitine (9), deoxyaconitine (10) and deoxyjessaconitine (11), in yields of 87, 88 and 85%, respectively. When the same reaction as used for the syntheses of the 3, 13-dideoxy compounds was done at refluxing temperature, 3, 13, 15-trideoxy compounds, that is, 3, 13, 15-trideoxymesaconitine, 3, 13, 15-trideoxyaconitine and 3, 13, 15-trideoxyjesaconitine, were obtained in yields of 83, 83 and 88%, respectively.
在四氢呋喃中,氢化钠、催化量的咪唑、二硫化碳和碘甲烷与中乌头碱(1)在室温下反应,生成二-O-(S-甲基)硫代碳酸酯(5)。使用三丁基锡氢化物对5进行还原裂解,以83%的高产率得到异翠雀碱(3)。乌头碱(2)和杰斯乌头碱(6)经过完全相同的反应,分别以85%和86%的产率得到垂头碱(4)和3,13-二脱氧杰斯乌头碱(7)。以乙醚代替四氢呋喃进行相同反应,分别以87%、88%和85%的产率得到3-脱氧化合物次乌头碱(9)、脱氧乌头碱(10)和脱氧杰斯乌头碱(11)。当在回流温度下进行合成3,13-二脱氧化合物的相同反应时,分别以83%、83%和88%的产率得到3,13,15-三脱氧化合物,即3,13,15-三脱氧中乌头碱、3,13,15-三脱氧乌头碱和3,13,15-三脱氧杰斯乌头碱。