Chapter 11 - Carbonyl Compounds and Redox Reactions

dehydrogenation

a reaction in which an organic compound loses two hydrogen atoms, creating an alkene grp

• alkane loses 2 hydrogen atoms to make room for additional carbon-carbon bond to become alkene

• is an oxidation reaction

[H]

symbol that is used to represent a hydrogen atom that is attached to an organic molecule

oxidation reaction

any reaction that removes 2 hydrogen atoms from an organic compound

hydrogenation reaction

a reaction in which an alkene or alkyne gains hydrogen atoms, becoming an alkane or an alkene respectfully

• reverse of the dehydrogenation reaction

• is a reduction reaction

reduction reaction

any reaction in which hydrogen atoms are added to an organic molecule

summary

• oxidation reactions remove hydrogen atoms from organic molecule

• reduction reactions add hydrogen atoms to an organic molecule

• whenever one compound is oxidized, another must be reduced

oxidation of an alcohol

• remove 2 hydrogen atoms from the organic compound, and we convert a single bond to a double bond

• carbonyl group is the product

carbonyl group

C = O

oxidation of an alkane

product has carbon-carbon double bond

teritiary alcohols cannot be oxidized

to be oxidized an alcohol must have a hydrogen atom directly bonded to the carbon of the functional group

• picture cannot be oxidized because there is no H atom bonded to the functional group carbon

classification of alcohols

1. methanol

2. primary

3. secondary

4. tertiary

methanol

carbon atoms adjacent to the functional grp: 0

general structure (adjacent carbon atoms are shown in red

primary

carbon atoms adjacent to the functional grp: 1

general structure (adjacent carbon atoms are shown in red

secondary

carbon atoms adjacent to the functional grp: 2

general structure (adjacent carbon atoms are shown in red

tertiary

carbon atoms adjacent to the functional grp: 3

general structure (adjacent carbon atoms are shown in red

carbonyl groups

compounds that contain carboxyl grp can be reduced

• double bond becomes a single bond and carbon and oxygen of the original group each gain a hydrogen atom

specific example of a reduction

reduction reactions often convert an achiral molecule into a chiral molecule

aldehydes

oxidized PRIMARY alcohol or methanol with the product of a carbonyl group on the END of the carbon chain

aldehyde group

the carbonyl grp plus its neighboring hydrogen

to name an aldehyde using IUPAC rules

1. first name the carbon chain, include the aldehyde chain

2. replace the final “-e” of the alkane name w “-al”

3. do not need to write a # to show the location of the functional grp bc aldehyde group must always be at the end of the carbon chain

drawing aldehydes

drawn structure of an aldehyde, they abbreviate the aldehyde group to -CHO

acetaldehyde

trivial name for ethanal aldehyde

formaldehyde

trivial name for methanal

ketones

compounds with structure where oxidized SECONDARY alcohol, the product has a carbonyl group in the interior of carbon chain

ketone grp

is the funcitonal grp

To name a ketone using IUPAC rules

1. start with naming carbon chain

2. replace the final “-e” w/ “-one”

3. have to include a # to show location of functional ketone grp because the oxygen atom can be bonded to any internal carbon atoms in a ketone (# chain from side thats closest to functional grp)

cyclic ketone

naming it don’t use a #

drawing line structure of an aldehyde or ketone

• draw carbon chain as a zigzag line, then add oxygen atom with its double bond

• for aldehydes add functional grp hydrogen to structure

aldehydes and ketones have similar physical proerties

1. boiling points

2. solubilities

boiling points

• molecules containing a carbonyl group are more strongly attracted to one another

• aldehydes and ketones have HIGHER BP’s then normal hydrocarbons but LESS than alcohols (hydrogen bonds

• all common aldehydes and ketones are liquids at 20 degrees

solubilities

• aldehydes and ketones have similar solubilities to alcohol and are greater than regular hydrocarbons

  • 1. alcohol, 2. A and K, 3. regular hydrocarbons

• increase # of carbon atoms = decrease

• increase of carbonyl grps = increase