ABSTRACT
Isomerism gives rise to isomers that are molecules with the same chemical formula but different structural parameters or different spacial structures. As for structural isomerism, there are three types: chain isomerism, position isomerism, and functional isomerism. Stereoisomerism is related to specific arrangements of substituents where two isomers are differentiated by their spacial disposition. Geometric stereoisomerism in alkenes is more restricted than in cycloalkanes. Optical stereoisomerism is related to the pair of isomers which have distinguished optical properties, although any other property is the same for both isomers. General cases of axial chirality are substituted allenes or substituted spirobicycloalkanes. Chirality comes from Greek, meaning “hand” which is the iconic example of chirality. In chemistry, enantiomorphs are called entantiomers. The types of enantiomers were mentioned in the previous subsection. Except for enantiomers, all other molecules are achiral.
