(S)-4-Chloro-4-ethyl-1H-pyrano(3',4':6,7)indolizino(1,2-b)quinoline-3,14(4H,12H)-dione 1H-Pyrano(3',4':6,7)indolizino(1,2-b)quinoline-3,14(4H,12H)-dione, 4-chloro-4-ethyl-, (S)- 7691-05-6