Topic 14: Alkenes Flashcards
Alkene
Unsaturated hydrocarbon
Test for alkene
Add bromine water goes orange to colourless
General formula
CnH2n
c=c shape
planar - restricted rotation so ez isomerism
Stereoisomerism and type
EZ (geometric) Same structural formula but atoms/ groups have different spacial arrangements
Both groups attatched to same c=c on LHS/RHS able to switch
NO
Z isomer
Zame Zide
E isomer
Opposite side
Cahn-Ingold-Prelog (CIP)
(EZ Isomers)
Priority to largest Ar on each side - first atom of group, if both carbon see what the next largest atom is down the chain.
Electrophile
An electron pair acceptor
Electrophilic addition
Electrophiles attacking double bonds of alkenes
Electrophiles example
Br2
HBr
concentrated
H2SO4
Electrophilic addition
Arrow from double bond to delta positive side of electrophile
Arrow from electrophile bond to delta negative side of electrophile
Carbocation intermediate with added Br.
Arrow from nucleophile to carbon
End haloalkane.
Deciding which carbocation is made in electrophilic addition
More stable, more alkyl groups attached to carbocation better to have secondary carbocation than primary
Primary carbocation
One alkyl group 1* (degrees)
Major product
More stable carbocation was produced
Molecule made from electrophilic addition of h2so4
Ethylhydrogensulphate
Product of electrophilic addition of h2so4 with water makes
An alcohol
Positive inductive affect
