???: ,??:CnH2n.

1
??? ???
??????????????
2

• ??? ,??CnH2n.
• ??? ?????
• ??????

CC ??610kJ/mol
3
(No Transcript)
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p-Bonding(Bonding molecular orbital)

5
???????
????
?????
6
??? ??????????

• ?????????
• ??????????????????????
• ????5??????

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?(cis)??????????????????(trans)?????
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???????

• 1. ??????????????(??),??????????????
• 2. ???????????????
• 3. ????????????,??????????????

5,5-???-1-??
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Ethene
Propene
Ethylene
Propylene
1-Butene
2-Butene
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2-Methyl-2-butene
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6-Methyl-2-heptene
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6-Methyl-2-heptene
13
??

• Ethyl CH2CH- Vinyl
• 1-Propenyl
• 2-Butenyl
• 2-Pentenyl

Allyl
Isopropenyl(for 1-methylvinyl)
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E-Z Nomenclature

15

E-Z Nomenclature Rules

• SEQUENCE RULE 1 If the four atoms directly
  attached to the double bond are all different,
  priority depends on atomic number, with the atom
  of higher atomic number receiving the higher
  priority.
• COROLLARY If two atoms are isotopes of the same
  element, the heavier isotope receives the higher
  priority.

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E-Z Nomenclature Rules

• SEQUENCE RULE 2 If the relative priority of two
  groups cannot be decided by Rule 1, it shall be
  determined by a similar comparison of the next
  atoms in the groups (and so on, if necessary),
  working outward in ranks from the double bond.

17

E-Z Nomenclature Rules

• To complete the IUPAC name of a particular
  isomer, enclose the (E) or (Z) symbol in
  parentheses and place it at the front of the
  entire name of the compound. Separate the (E) or
  (Z) symbol from the rest of the name with a
  hyphen.

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Examples
Question (CH3)3C-? -CH2Cl????????
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trans-6-Methyl-3-propyl-2-octene
(Dont worry about trans until Chapter 4)
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Intention

• 1. Z?E??(Cis)??(Trans)??????????

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??? ???????

• ????????--????, ? ???,??????????????????,??????,?
  ??????????

• Remember it!

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Addition Reactions
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??????
??????????????Raney Ni Fe?Cr?Cu.
??????????? ????
????
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Hydrogenation of Alkenes
Also PtO2 -- sometimes Ru, Rh, or Re
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HYDROGEN ADSORBS ON THE SURFACE OF THE CATALYST
.
n H2 Pt
Pt(H )2n
finely-divided particles dispersed in solution
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MECHANISM OF HYDROGENATION
CATALYST
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MECHANISM OF HYDROGENATION
HYDROGEN ADSORBS
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MECHANISM OF HYDROGENATION
ALKENE APPROACHES
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MECHANISM OF HYDROGENATION
ALKENE PICKS UP TWO HYDROGENS
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MECHANISM OF HYDROGENATION
R
R
R
R
ALKANE IS FORMED
.
.
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???1mol???????????????

• ?????????????????
• ???????????,??????
• R2CCR2gtR2CCHRgtRCHCHRgt
• RCHCH2gtCH2CH2.
• 2-????gt?-2-??gt?-2-??gt1-???

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Alkene Stability

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??????
Electrophilic Addition to a Double Bond
????(E)??????,??????
34

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1. ?????
???????????????????(???)??????????????? 1)??????
(Addition of Hydrogen Halides)
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?????????????HIgtHBrgtHCl
Markovnikov Addition to an Alkene
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Markovnikov Addition to an Alkene

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Markovnikov Rule

• In the ionic addition of an acid to the
  carbon-carbon double bond of an alkene, the
  hydrogen of the acid attaches itself to the
  carbon atom which already holds the greater
  number of hydrogens.
• Them that has, gets!
• The richer get richer! (V. W.
  Markovnikov -- 1838 - 1904)

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REGIOSELECTIVE REACTION
???????
C
H
C
H
C
H
3
3
3
HCl

C
C
H
C
H
C
C
H
C
H

C
H
C
H
C
H
3
2
3
3
3
2
C
l
C
l
major
minor
one of the possible products is formed in larger
amounts than the other one
REGIOSPECIFIC
Compare
only one of the possible products is formed
(100).
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MARKOVNIKOV RULE
When adding HX to a double bond the hydrogen of
HX goes to the carbon which already has the most
hydrogens

C
H
C
H
3
2
C
l
HCl
..... conversely, the anion X adds to the
most highly substituted carbon ( the carbon
with most alkyl groups attached).
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KARASCH??(??????
????????,????????????,?????Anti-Markovnikov rule.
Reading Assignment ?????
42
2)?????
????????????Markovnikov rule.
???????????,???????
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Addition of Sulfuric Acid to an Alkene
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Addition of Water to an Alkene
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????
2. ?????
????????????F2gtCl2gtBr2gtI2(???)
Br/CCl4????????
ICl ? IBr???(X2H2O)????????????????
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Halohydrin Formation
??????
HOBr
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3. ??????(??????B-H?????????????)?C. H. Brown??
48
????????????????????,??????????????????????????
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Sia2BH,thBH2(HBH2), 9-BBN

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??
??1.??????????????2.????,????3.???4.???????

????
51
?1
52
??????
?-1,2-??

• 1. ?KMnO4?OsO4 (????)??

???????????,????????,????????????????,???????,????
?
??????,??????,????????
?KMnO4??????????
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2. ???
??,?H2O2??,????????????

H2O
54
????????????????

• ????????
• 1)Zn/H2O
• 2)H2,Pd
• ?????????

???????
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(No Transcript)
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3.????
Organic Reaction
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??????

• ??????????????????????????????

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Polymerization of Propene
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???-H ????

• 1. ??

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?-H????(?????)
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2. ??

???
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??? ?????

• ??????
• 1. ?????HX
• 2. ??????X2
• 3. ??H2O

?-??
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Saytzeff Rule
???????
????
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??? ???????????

• ??????

????
????
????????,?????????????????
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Mechanism of Bromination of an Alkene
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CYCLIC BROMONIUM ION
??????
note size of bromine
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BRIDGED BROMONIUM ION
Br

Br
Br
bridging blocks approach from this side
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BRIDGED BROMONIUM ION
-
symmetric ion - bromide ion could add to either
side left or right
B
r
H
H

B
r
-
-
B
r
B
r
H

H
H

H
B
r
B
r
resonance contributing structures
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FORMATION OF ENANTIOMERS
symmetric intermediate
Addition could also start from the top with
bromide attacking the bottom.

ENANTIOMERS
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2. ???HX??

E ElectrophileNu Nucleophile General
Mechanism The first step requires a powerful
electrophile to attract the pi bond electrons,
which then forms a carbocation. A nucleophile
quickly adds to the carbocation to form the
monosubstituted product.
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3. Markovnikov Rule and Stability of Carbocation
?-????

• ??
• 2)???????
• ?(3?)gt?(2 ? )gt?(1 ? )gtCH3

??-p???????
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COMPETING PATHWAYS
rate-determining step
????
higher energy intermediate
slower
faster
lower energy intermediate
rate-determininng (slow) step
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Hyperconjugation
???
H
H
C
C
H
H
H
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CARBOCATION STABILITY
HYPERCONJUGATION
????????
H
electrons in an adjacent C-H s bond help to
stabilize the positive charge of the carbocation
by proximity (overlap)
..

R
C
C
H
R
H
lowest energy
highest energy
lt
lt
tertiary
secondary
primary
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4. ?????
??????

• Anti-Markovnikov Rule

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Problem Assignment

• 1.?????????????????1,2-?????,??2-????1-?-2-???,???
  ?
• 2.??????

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Homework Assignment

• Pp75 2.(1,3,6) 3(3,5) 568??(2)(b)?CH3CH2
  CH2OH1012(???????,???????,????,???????,????)
• 1315???????
• ???1820