38136-92-4 Spiro(5H,6H-5a,9a-(iminomethano)-1H-cyclopent(f)indolizine-7(8H),2'-(2H)indole)-3',5,10(1'H)-trione, 2,3,8a,9-tetrahydro-8,8-dimethyl-, (2'S,5aR,8aS,9aR)-