what is steric hindrance

Dear Student

 

Steric hindrance: The prevention or retardation of chemical reaction because of neighboring groups on the same molecule; for example, ortho-substituted aromatic acids are more difficult to esterify than are the meta and para substitutions.

If a tertiary halide is used, elimination competes over substituion and an alkene is formed instead of ether. This is because of steric hinderance. We use an alkoxide which has to donate a pair of electrons to the tertiary carbon. Since the tertiary carbon is surrounded by three alkyl groups , it leads to overcrowding around the carbon atom. Hence the alkoxide cannot approach the carbon properly instead approaches the side carbon and forms an alkene.

 

Regards,

Topper team