Summary When a primary base adds to a carbodiimide to yield a guanidine, only one hydrogen atom of the base shifts to a nitrogen atom of the carbodiimide. This rule is established by study of the lone isomer obtained with a symmetrical carbodiimide and also of the two isomers always obtained with the symmetrical carbodiimide. This knowledge leads to determination of location of gamma double bonds. Twelve pairs of isomers were ...
