2-Oxabicyclo[2.2.2]octane-6-carboxylic acid, 5,5'-(methylenedi-3-cyclohexene-4,1-diyl)bis[7-[[bis(2-chloroethyl)amino]methyl]-3,8-dioxo-, diethyl ester 2-Oxabicyclo[2.2.2]octene-6-carboxylic acid, 5,5'-(methylenedi-3-cyclohexene-4-1-diyl)bis[7-[[bis[7-[[bis(2-chloroethyl)amino]methyl]-3,8-dioxo-, diethylester 2-Oxabicyclo[2.2.2]octene-6-carboxylic acid, 5,5'-(methylenedicyclohexen-4,1-ylene)bis-[7-[[bis(2-chloroethyl)amino]methyl-3,8-dioxo-, diethyl ester NSC135111