ALKANE ALKYL HALIDE ALKYL HALIDE ALKENE
Halogenation of Alkanes - Ch 4, 8 E2 Reaction of Alkyl Halides - Ch 8, 9
Cl2 Cl
Br Na+ base
+ HCl + H-base + Na+ Br
heat or
light
radical mechanism (write on back of card) E2 mechanism (write on back of card)
only works with 2o and 3o alkyl halides
only works with Cl2 and Br2 with 2o alkyl halides, use (CH3)3COK to avoid SN2 reactions
must have a strong base (usually alkoxide )
usually results in multiple products constitutional isomers may form if more than one ! hydrogen is
exceptions: when all carbons are the same (as above) available
when one carbon forms a more stable radical anti elimination: when both carbons are stereocenters, only one
(3o, benzyl, or allyl) stereoisomer is formed
ALKYL HALIDE ALKYNE ALKYL HALIDE NITRILE
SN2 Reaction of Alkyl Halides with Acetylide Anions - Ch 8, 11 SN2 Reaction of Alkyl Halides with Cyanide - Ch 8, 22
HC C Na+ Na+ C N
Br + Na+ Br Br + Na+ Br
N
SN2 mechanism (write on back of card)
SN2 mechanism (write on back of card)
alkyl halides must be 1o to avoid E2 reactions
alkyl halides must be 1o to avoid E2 reactions
internal alkynes may be formed by using terminal alkynes
which have been deprotonated with NaH or NaNH2
, ALKYL HALIDE ALCOHOL ALKYL HALIDE, ETHER
ALCOHOL
SN2 Reaction of Alkyl Halides with Hydroxide - Ch 8, 12 SN2 Reaction of Alkyl Halides with Alkoxides - Ch 8, 14
Na+ OH Na+ O
Br OH + Na+ Br Br O + Na+ Br
SN2 mechanism (write on back of card)
SN2 mechanism (write on back of card)
alkyl halides must be 1o to avoid E2 reactions
alkyl halides must be 1o to avoid E2 reactions
alkoxides are formed by reacting alcohols with NaH,
Na (methyl, 1o) or K (2o)
3o alcohols cannot be used as they are too bulky to react in
SN2 mechanisms
ALKENE ALKYL HALIDE ALKENE ALKYL HALIDE
Addition Reaction of HX to an Alkene - Ch 9 Addition Reaction of HX to an Alkene with Organic Peroxide - Ch 9
Cl HBr
HCl Br
ROOR
carbocation mechanism (write on back of card) radical mechanism (write on the back of card)
HCl, HBr, and HI may be used only HBr may be used (HCl, HI go by carbocation mechanism)
subject to rearrangements not subject to rearrangements
halogen goes to the more substituted side of the C=C halogen goes to the less substituted sideof the C=C
all possible stereoisomers are formed all possible stereoisomers are formed
, ALKENE ALCOHOL ALKENE ALCOHOL
Acid Catalyzed Addition of Water to an Alkene - Ch 9 Addition of Water to an Alkene by Oxymercuration-reduction - Ch 10
H2SO4 OH
Hg(OAc)2 OH NaBH4 OH
H2O HgOAc
H2O
carbocation mechanism (write on back of card)
reaction takes place in two steps
acid is catalytic; it must have a non-nucleophilic
conjugate base - phosphoric acid may also be used not subject to rearrangements
subject to rearrangements OH goes to the more substituted side of the C=C
OH goes to the more substituted side of the C=C all possible stereoisomers are formed
all possible stereoisomers are formed
ALKENE ALCOHOL ALKENE ALKANE
Addition of Water to an Alkene by Hydroboration-oxidation - Ch 10 Hydrogenation of an Alkene - Ch 10
H2O2 H2
BH3-THF
B OH
Pd/C
NaOH
excess hydrogen is always present (all C=C react)
reaction takes place in two steps
palladium is catalytic; other metals such as platinum or
only 1/3 equivalent of borane-THF is needed rhodium may be used
not subject to rearrangements the metal catalysts are pyrophoric (must be handled with
care)
OH goes to the less substituted side of the C=C
H and OH are added to the same side (syn addition)
Halogenation of Alkanes - Ch 4, 8 E2 Reaction of Alkyl Halides - Ch 8, 9
Cl2 Cl
Br Na+ base
+ HCl + H-base + Na+ Br
heat or
light
radical mechanism (write on back of card) E2 mechanism (write on back of card)
only works with 2o and 3o alkyl halides
only works with Cl2 and Br2 with 2o alkyl halides, use (CH3)3COK to avoid SN2 reactions
must have a strong base (usually alkoxide )
usually results in multiple products constitutional isomers may form if more than one ! hydrogen is
exceptions: when all carbons are the same (as above) available
when one carbon forms a more stable radical anti elimination: when both carbons are stereocenters, only one
(3o, benzyl, or allyl) stereoisomer is formed
ALKYL HALIDE ALKYNE ALKYL HALIDE NITRILE
SN2 Reaction of Alkyl Halides with Acetylide Anions - Ch 8, 11 SN2 Reaction of Alkyl Halides with Cyanide - Ch 8, 22
HC C Na+ Na+ C N
Br + Na+ Br Br + Na+ Br
N
SN2 mechanism (write on back of card)
SN2 mechanism (write on back of card)
alkyl halides must be 1o to avoid E2 reactions
alkyl halides must be 1o to avoid E2 reactions
internal alkynes may be formed by using terminal alkynes
which have been deprotonated with NaH or NaNH2
, ALKYL HALIDE ALCOHOL ALKYL HALIDE, ETHER
ALCOHOL
SN2 Reaction of Alkyl Halides with Hydroxide - Ch 8, 12 SN2 Reaction of Alkyl Halides with Alkoxides - Ch 8, 14
Na+ OH Na+ O
Br OH + Na+ Br Br O + Na+ Br
SN2 mechanism (write on back of card)
SN2 mechanism (write on back of card)
alkyl halides must be 1o to avoid E2 reactions
alkyl halides must be 1o to avoid E2 reactions
alkoxides are formed by reacting alcohols with NaH,
Na (methyl, 1o) or K (2o)
3o alcohols cannot be used as they are too bulky to react in
SN2 mechanisms
ALKENE ALKYL HALIDE ALKENE ALKYL HALIDE
Addition Reaction of HX to an Alkene - Ch 9 Addition Reaction of HX to an Alkene with Organic Peroxide - Ch 9
Cl HBr
HCl Br
ROOR
carbocation mechanism (write on back of card) radical mechanism (write on the back of card)
HCl, HBr, and HI may be used only HBr may be used (HCl, HI go by carbocation mechanism)
subject to rearrangements not subject to rearrangements
halogen goes to the more substituted side of the C=C halogen goes to the less substituted sideof the C=C
all possible stereoisomers are formed all possible stereoisomers are formed
, ALKENE ALCOHOL ALKENE ALCOHOL
Acid Catalyzed Addition of Water to an Alkene - Ch 9 Addition of Water to an Alkene by Oxymercuration-reduction - Ch 10
H2SO4 OH
Hg(OAc)2 OH NaBH4 OH
H2O HgOAc
H2O
carbocation mechanism (write on back of card)
reaction takes place in two steps
acid is catalytic; it must have a non-nucleophilic
conjugate base - phosphoric acid may also be used not subject to rearrangements
subject to rearrangements OH goes to the more substituted side of the C=C
OH goes to the more substituted side of the C=C all possible stereoisomers are formed
all possible stereoisomers are formed
ALKENE ALCOHOL ALKENE ALKANE
Addition of Water to an Alkene by Hydroboration-oxidation - Ch 10 Hydrogenation of an Alkene - Ch 10
H2O2 H2
BH3-THF
B OH
Pd/C
NaOH
excess hydrogen is always present (all C=C react)
reaction takes place in two steps
palladium is catalytic; other metals such as platinum or
only 1/3 equivalent of borane-THF is needed rhodium may be used
not subject to rearrangements the metal catalysts are pyrophoric (must be handled with
care)
OH goes to the less substituted side of the C=C
H and OH are added to the same side (syn addition)
