Experiments towards the total synthesis of five-membered D-ring ergot alkaloid analogues.
作者:George B. Okide
DOI:10.1016/s0040-4020(01)80221-0
日期:——
N-methylaminopropionitrile yielded a derivative, 4-N-methyl-N-2′-cyanoethyl)amino-1-benzoyl-2,2a,3,4-tetrahydrobenz[cd]indol-5H-(1H)-one which could not be cyclized to the desired five-membered D-ring ergot analogue. In a different approach the 4-methylamino derivative was prepared via the carbamate and the corresponding oxazolinone. However, introduction of the requisite side-chain for the construction
已知的三环酮,科恩菲尔德酮(5)1,是通过从商业上可获得的吲哚-3-丙酸进行常规操作的改进而以大大提高的产率制备的。与N-甲基氨基丙腈直接缩合,生成衍生物4- N-甲基-N -2'-氰乙基)氨基-1-苯甲酰基-2,2a,3,4-四氢苯并[cd]吲哚-5H-(1H)-无法将其环化为所需的五元D环麦角类似物。以另一种方式,通过以下方法制备4-甲基氨基衍生物:氨基甲酸酯和相应的恶唑啉酮。但是,为D形环的构造引入必要的侧链失败。最后,在三环酮的C-4处存在酰胺取代基的情况下,通过在C-5处引入双碳链,在Cope反应下获得了两个五元D环类似物。