Formation and reductive ring opening reactions of indolyl bicyclic-isoxazolidines-II:7 access to novel natural product analogs
作者:Gagandeep Singh、Tilak Raj、Vivek Gupta、Mohan Paul Singh Ishar
DOI:10.1016/j.tetlet.2016.09.011
日期:2016.10
Attempted reductive cleavage of indolyl-bicyclic-isoxazolidines (4a,b; R = benzyl, phenyl) with ammonium formate, methanol-THF solvents, at ambient temperature, in the presence of Pd/C lead to facile synthesis of indolyl-α-hydroxy-γ-lactams (5a–b), derived from reductive cleavage of the NO bond of bicyclic-isoxazolidines, followed by intramolecular recyclization. On the other hand, reaction of 4c (R = ethyl)
在环境温度下,在Pd / C存在下,尝试用甲酸铵,甲醇-THF溶剂还原吲哚基-双环-异恶唑烷(4a,b; R =苄基,苯基),导致容易合成吲哚基-α-羟基-γ-内酰胺(5a – b),源自双环异恶唑烷的N O键的还原性裂解,然后进行分子内环化。另一方面,在相同条件下4c(R =乙基)的反应遵循不同的过程,从而得到6,这是天然存在的海洋生物碱-皂素的类似物。提供了由DFT计算支持的观察到的反应行为的机械原理。