Lecture 8 Flashcards
What is the bonding in alkenes?
Two sp2 orbitals overlap to form a sigma bond between two carbon atoms.
Two 2p orbitals overlap to form a pi bond between the two carbon atoms.
S orbitals in hydrogen overlap with the sp2 orbitals in carbon to form CH bonds.
Due to the bonding in alkenes what is the resulting shape of an alkene?
Planar
Bond angle- 120o.
What is the IUPAC suffix for an alkene?
“ene”
What is the older nomenclature suffix for an alkene?
“ylene”
What is geometric isomerism and example of?
STEROISOMERISM
What causes geometric isomerism?
Occurs due to the RESTRICTED ROTATION around the Carbon- Carbon double bond.
When is it E isomerism?
Higher ranked substituents on OPPOSITE sides.
When is it Z isomerism?
Higher ranked substituents on SAME side.
In the elimination of HX from haloalkanes, what happens?
There is a loss of H+ and X- ions from ADJACENT carbons, forming a new pi bond.
What is the reagent and reaction conditions for the haloalkane to alkene (elimination)?
REAGENT: Alcoholic KOH/ NaOH
CONDITIONS: Reflux in alcoholic solution.
What is the reagents for dehalogenation of vicinal dibromides?
What type of reaction is this?
REAGENTS: NaI and Zn/HOAc- Redox Reaction.
What happens in the reaction of dehydration of alcohols?
Removal of Water.
What is the reagent and reaction conditions for the dehydration of alcohol?
REAGENT: Catalytic acid- Eg. Sulfuric or Phosphoric acid.
CONDITIONS: Reflux (Depends on alcohol).
What side reaction might occur alongside the dehydration of alcohols?
Rearrangement Reaction
In the Krebs Cycle what reaction occurs between citric acid to ascontic acid?
Elimination of water.