These two compounds exhibit a stereoisomeric relationship.
Tips
memory
Parse it as 立体 (three-dimensional) + 异构 (different structure). Contrast with 构造异构 (constitutional isomerism, where the connectivity itself differs).
culture
Specialist chemistry term. The thalidomide tragedy of the late 1950s is the classic real-world cautionary tale of why stereoisomerism matters: one mirror-image enantiomer was therapeutic, the other caused birth defects.
