Alkene Reactions Flashcards
generally classified as unsaturated hydrocarbon because the presence of multiple bonds
alkene and alkyne
organic compound that must have at least one sp2 hybridization carbon atom or -C=C.
alkene
geometry of alkene
planar
geomtery of alkyne
linear
angle of bonds of alkene
120 degrees
angle of bonds of alkyne
180
simplest alkene
ethene
simplest alkyne
ethyne
must have at least one sp hybridized carbon atom or -C≡C-
alkyne
has a suffixes modified to -ene
alkene
named using the IUPAC system using -yne
alkyne
name the alkyne and alkene
grade yourself accordingly
For compounds containing both a double bond and a triple bond, priority is given to the what
alkyne
suffix of compounds containing both a double and trible bond
-enyne
However, if the double bond and the triple bond will have the same position in the numbering the carbon chain, then priority is given to the
double bond
The double bond will receive the ___ in terms of position
lower number
C=C- makes alkene relatively more reactive than alkane
presence of pi electrons
can undergo electrophilic addition reaction with the general mechanism shown below
alkene
involves the breaking of pi bonds to form two new single bonds
electrophilic addition reaction
Reaction involves an electrophile which is an electron pair acceptor
electrophilic reaction
intermediate formed in a electrophilic addition reaction
carbocation
can be primary, secondary, tertiary, formed during electrophilic addition reaction
carbocation
determine the type of carbocation in ppt
grade yourself accordingly
most stable followed by secondary and the least is primary carbocation
tertiary carbocation
one carbocation is formed, this attacks the carbocation to form the product as shown in the mechanism
nucleophile
types of alkene reaction
Halogenation
Hydrogenation
Hydrohalogenation
Halohydrin formation
Acid catalyzed hydration
Oxidation
Hydration
determine the type of alkene reaction
grade yourself accordingly
this reaction follows anti-Markovnikov’s Rule because it follows free radical mechanism instead of a carbocation intermediate
addition of HBr in the presence of peroxide
the addition of -H to the -C=C follows this rule
Markovnikov’s rule
states that “hydrogen is added to the carbon with the most hydrogens and halide is added to the carbon with the least hydrogens”, this will form a more stable carbocation
Markovnikov’s rule
still follows Markonivkov’s rule and is acid catalyzed
hydration of alkenes
rearrangement is possible via this to form a more stable carbocation
hydride shift
follows anti-addition and forms vicinal dihalide
Halogenation
halogens that can be added to alkene
Cl or Br
addition of halogen in the presence of water
halohydrin formation
Follows Markovnikov’s rule wherein the halogen adds to the carbon with the most number of hydrogen atoms
halohydrin formation
alkenes transformed to alkanes by addition of hydrogen gas in the presence of a metal catalyst
hydrogenation
Most common metal catalyst are:
nickel
platinum
palladium
oxidation of alkene via this process forms aldehyde and ketone
ozonolysis
breaks the double bond in ozonolysis
oxidative cleavage
Considered a weak oxidation of alkene
ozonolysis
common reducing agents
Zinc (Zn)
dimethyl sulfide (CH3)2S)
stronger oxidizing agent and in acidic medium results in formation of carboxylic acid and ketone
KMnO4
produces CO2 in oxidation with KMnO4
terminal alkenes
formed in a cold alkaline medium
diol
