1. ALKENES AND CYCLOALKENES
Compounds with C - C ,154 nm and C – H bonds
C = C 0, 134 nm and =C-H bonds
Bonding energy C – C kJ/mol s - bond
C = C kJ/mol D = 259 kJ/mol p - bond

2. ALKENES AND CYCLOALKENES
Nomenclature
ethenyl- , vinyl-
ethene, ethylene
prop-2-en-1-yl, allyl-
propene,
propylene
prop-1-en-1-yl
butene
prop-1-en-2-yl
but-2-ene
Geometric isomerie
application cis- and trans- is suitable only for simple molecules
cis-but-2-ene trans-but-2-ene

3. ALKENES AND CYCLOALKENES
STABILITY of alkenes
trans-
cis-
HEAT OF HYDROGENATION
stability of trans-isomer is higher

4. ALKENES AND CYCLOALKENES
the more the systeme at the double bond is branched, the more is stable

5. ALKENES AND CYCLOALKENES only stable is trans-cyclooctene
all cycloalkenes with less than 6 atoms in a ring are only known as cis- isomers
only stable is trans-cyclooctene

6. Reactions are stereospecific
ALKENES AND CYCLOALKENES
THE MAIN DIRECTION OF ALKENE REACTIVITY
ADDITION REACTION
Reactions are stereospecific
During addition of symmetrical molecule to non-symmetrically substituted olefine
enantiomers are created – reaction is stereospecific- trans- (anti-) addition

7. Stereospecific mechanism of additions

8. Regiospecific mechanism of additions

9. Regiospecific mechanism of additions

10. Regiospecific mechanism of additions