How are alkenes obtained?

1 Answer
Apr 30, 2016

Alkenes are obtained by elimination reactions

Explanation:

Alkenes are obtained by elimination reactions Following are some examples.

  • Dehydration of Alcohol
    In this process alcohol is dehydrated
    (1) byheating with conc.H_2SO4 at 450K or by P_2O_5
    or (2) by passing alcohol vapor over heated Alumina,Al_2O_3

Reaction
RCH_2CH_2OH->RCH=CH_2+ H_2O

  • Dehydrohalogenation
    In this process Alkyl halide except fluoride is reacted with alcoholic KOH
    Reaction
    RCH_2CH_2X->RCH=CH_2+ HX (where X =Cl,Br,I)

- Dehalogenation
In this process vicinal or geminal dihalide except fluoride is heated with alcoholic Zn

Reaction
RCHXCH_2X+Zn->RCH=CH_2+ ZnX_2 (where X =Cl,Br,I)

Other process like cracking of alkane is also there