Advices For Studying Organic Chemistry

2) trans-Cyclooctene is chiral and exists as a pair of enantiomers.

CH 2

CH 2

H 2 C CH 2

HC

HC

H 2 CCH 2

CH 2

H 2

C

H 2 C

C

H 2 C

CH

2

CH 2

C

H

H H^2 C

H 2

C

CH 2

C

CH 2

CH

2

H 2 C

C

H

H

cis-Cyclooctene trans-Cyclooctene
Figure 7.5 The cis- and trans forms of cyclooctene.

7.5 SYNTHESIS OF ALKENES VIA ELIMINATION REACTIONS

1. Dehydrohalogenation of Alkyl Halides

CC

H

HH

HH

X − HX

CC

H

H

H

H

base

2. Dehydration of Alcohols

CC

H

HH

H H

OH

H+, heat

− HOH

CC

H

H

H

H

3. Debromination of vic-Dibromides^

CC

Br

HH

H H

Br −^ Zn

Zn, C

Br 2

CC

H

H

H

H

H 3 CH 2 OH

7.6 DEHYDROHALOGENATION OF ALKYL HALIDES