CH3-CH2-CH2-CH2Br →E2alc.KOH/∆ CH3-CH2-CH=CH2A; CH3-CH-CH=CH2→HBr CH3-CH2-CHBr-CH3B;                                                       Markonikov's product CH3-CH2-CHBr-CH3 →E2alc.KOH  CH3-CH=CH-CH3C ;                                                                     Saytzeff product