918958-13-1 Pyrano[3,4-b]indole-1-acetic acid, 1,8-diethyl-1,3,4,9-tetrahydro-,compd. with 1,1,2,2-ethenetetracarbonitrile (1:1) 918958-14-2 Pyrano[3,4-b]indole-1-acetic acid, 1,8-diethyl-1,3,4,9-tetrahydro-,compd. with 2,3,5,6-tetrachloro-2,5-cyclohexadiene-1,4-dione (1:1)