Alkenes Flashcards
What are alkenes?
Hydrocarbons with carbon-carbon double bonds
alkenes are sometimes called…
Olefins
Many alkenes are found in what?
Plants and animals
What is the largest-volume industrial organic compound?
Ethylene
What is ethylene used to make?
Polyethylene and a variety of other industrial and consumer chemicals
What is pinene?
A major component of turpentine, the paint solvent distilled from extracts of evergreen trees
Which bonds are more stable?
Single bonds
What are the most common reactions of double bonds?
Transform the pi bond into a sigma bond
What is catalytic hydrogenation?
Example of addition reaction → pi bond and the sigma bond converted into 2 sigma bonds
Which bond is stronger and shorter
Alkenes → 152 kcal mol -1
1.33A
What bonds does C = C contain?
One sigma and one pi bond
Is rotation possible for a c=c?
No
Alkenes are saturated or unsaturated?
Unsaturated
Why is the product, an alkane, called saturated?
It cannot react with any more hydrogen
The presence of a pi bond decreases what?
The number of hydrogen atoms in a molecular formula → elements of unsaturation
One element of unsaturation corresponds to how many fewer hydrogen atoms ?
Two
A compound with two, three, and four double bonds are named as what?
2 → diene
3 → triene
4 → tetraene
What is conjugated diene?
Double bonds that are separated by just one single bond
What is isolated diene?
Double bonds being separated by two or more single bonds
Isolated or conjugated diene is more stable?
Conjugated
Alkenes named as substituents are called what ?
Alkenyl
What are the common alkenyl substituents?
Vinyl, allyl,methylene, and phenyl groups
How is the phenyl group different?
Its aromatic and doesn’t undergo the typical reactions of Alkenes
What is application of polyene?
Antifungal drug
What is the best-known polyene antifungal drug?
Amphotericin B
What is the application of stereoisomers?
Drugs → quinine used for malaria,
stereoisomer of quinine, quinidine → treat irregular heartbeat
Trans cycloalkenes are unstable unless….
The ring is large enough ( at least 8 C)
All cycloalkenes are assumed to be cis or trans?
Cis
Ethylene also serves as what ?
Plant hormone → accelerating the ripening of fruit
What is the reaction of alkene?
Electrophilic addition
What is the markovnikovs rule ?
The addition of a proton acid to the double bond of an alkene results in a product with the acid proton bonded to the carbon atom that already holds the greater number of hydrogen atoms
Describe the oxidative addition of bromine to cyclohexene
The bromine color disappears because bromine adds across double bond
Added at right → no reaction
What is epoxied?
Three-membered cyclic ether, also called oxirane
What are epoxides valuable for?
Synthetic intermediates used for converting alkenes to a variety of other functional groups
An Alkene is converted to a peroxide by what?
Peroxyacid → a cardoxylic acid that has an extra oxygen atom
What is the application of epoxide?
Insecticides
What is the application of epoxide in drug metabolism?
What is the method of preparation of alkenes?
Catalytic cracking
What is catalytic cracking?
Heating a mixture of alkanes in the presence of catalyst ( aluminosilicates )
Alkenes formed by bond cleavage to give an Alkene and a shortened alkane
