Elimination reaction

“Secondary alkyl systems undergo, depending on conditions, both eliminations and substitutions by either possible pathway: uni- or bimolecular. Good nucleophiles favor S1 and E1.”

“Tertiary systems eliminate (E2) with concentrated strong base and are substituted in nonbasic media (S1.”

“Just as the chemistry of alkenes is dominated by addition reactions, the preparation of alkenes is dominated by elimination reactions. Additions and eliminations are, in many respects, two sides of the same coin.”