However, if both maleic and fumaric acid gave the dl pair or a mixture in which the
dl pair predominated, the reaction would be stereoselective, but not stereospecific.
If more or less equal amounts of dl and meso forms were produced in each case,
the reaction would be nonstereoselective. A consequence of these definitions is
that if a reaction is carried out on a compound that has no stereoisomers, it cannot
be stereospecific, but at most stereoselective. For example, addition of bromine
to methylacetylene could (and does) result in preferential formation of trans-1,2-
dibromopropene, but this can be only a stereoselective, not a stereospecific reaction.