Chapter 25 & 26 Notes, part II

Alkenes, Alkynes and Functional Groups

AlkenesUp to now, we have only talked about carbons

that are single bonded. They have been saturated—they have a hydrogen in every possible position.

Alkenes are hydrocarbons that contain at least one double bond in the carbon chain.

Naming AlkenesTo name an alkene, count the number of

carbons in the main chain and use the prefix, then end it in –ene.

If there is more than one spot where a double bond could occur, number it just like you would number a substituent.

AlkynesAn alkyne is a hydrocarbon that contains at

least one triple bond.

Both alkenes and alkynes are considered unsaturated, because more hydrogens could be added if the double or triple bonds were broken.

Naming AlkynesTo name an alkyne, count the number of

carbons in the main chain and use the prefix, then end it in –yne.

If there is more than one spot for a triple bond, number it just like you would number a substituent.

Functional GroupsA specific arrangement of atoms in an organic

compound that is capable of characteristic chemical reactions is called a functional group.

We will look at the structure and name of several functional groups.

Alcohols (R-OH)The functional group –OH is called a hydroxyl

group. A hydrocarbon with a hydroxyl group attached is an alcohol.

To name an alcohol, drop the –e ending from the parent alkane and add –ol.

If there is more than one spot where a hydroxyl group can go, number it just like a substituent.

Carboxylic acids (R-COOH)A carboxyl group is a carbon with an oxygen

double bonded to it and an oxygen single bonded to it and single bonded to a hydrogen.

To name a carboxylic acid, take the –e off of the end of the parent alkane and add –oic acid.

Amines (R-NH2)Amines are an ammonia based organic

compound. It consists of a carbon chain connected to an amine group.

Amines are closely related to amino acids—they are amines with a carboxyl group.

Amines are named by taking the parent alkane, drop the -e and adding the ending –amine.

Other Functional GroupsEthers R-O-R

O

Aldehydes R-C-H

O

Ketones R-C-R

O

Esters R-C-O-R