Quinolizidines. XXXII. A chiral synthesis of 3,4,5,6-tetradehydro-17-hydroxycorynanium, the zwitterionic structure assigned to an alkaloid from Aspidosperma marcgravianum
作者:Tozo Fujii、Masashi Ohba、Takako Ohashi
DOI:10.1016/s0040-4020(01)80544-5
日期:1993.2
The total synthesis of 3,4,5,6-tetradehydro-17-hydroxycorynanium [(+)−4], the zwitterionic structure assigned to an alkaloid from Aspidosperma marcgravianum, has been accomplished for the first time via a “lactim ether route”. The route started with an initial condensation between the lactim ether [(+)]−5] and 3-chloroacetylindole and proceeded through the lactam ester [(+)−23], lactam alcohol [(+)−24]
3,4,5,6-tetradehydro-17-hydroxycorynanium [(+)− 4 ]的总合成是通过“内酯醚途径”首次完成的,该两性离子结构是从马孢子虫中分配给生物碱的两性离子结构。。该路线以内酰胺醚[(+)]- 5 ]和3-氯乙酰吲哚之间的初始缩合开始,然后通过内酰胺酯[(+)- 23 ],内酰胺醇[(+)- 24 ],乙酰氧基内酰胺[ [ +)- 26 ],季亚胺盐[(+)- 25 ]和3,4,5,6-四氢17-羟基高ry酸高氯酸盐[(+)- 27 ]。在1合成的(+)- 4的1 H NMR光谱数据和比旋度的迹象与天然样品的报道不一致,从而使此A. marcgravianum生物碱的化学反应不完整。