Synthetic anthracyclines: regiospecific total synthesis of a D-ring indole analogue of daunomycin.

@article{Kita1990SyntheticAR,
  title={Synthetic anthracyclines: regiospecific total synthesis of a D-ring indole analogue of daunomycin.},
  author={Yasuyuki Kita and M Kirihara and M Sasho and Yoshiharu Fujii and J Sekihachi and R Okunaka and Yukiyoshi Tamura and K Shimooka},
  journal={Chemical & pharmaceutical bulletin},
  year={1990},
  volume={38 3},
  pages={585-9}
}
The 4-methoxy-5-methylpyrano[4,3-b]indole-1,3(4H,5H)-dione (9), prepared from methyl 3-methoxycarbonyl-1-methylindol-2-yl acetate (6), underwent a strong base-induced cycloaddition reaction with 2-chloro-6,6-ethylenedioxy-5,6,7,8-tetrahydro-1,4-naphthoquinone (11) to give the tetrahydronaphtho[2,3-b]carbazole-7,12-dione (10), regioselectively. The cycloadduct (10) was successfully converted to a D-ring indole analogue of daunomycin (1a).