OBJ 8.1-8.3 Aldehydes

OBJ 8.1-8.3 Aldehydes

and Ketones

Compare the structures of aldehydes and ketones 

OBJECTIVE 8.1

The carbonyl group

• Aldehyde: carbonyl group bonded to a hydrogen atom ( RCH=O )

• Ketone: carbonyl group bonded to two carbon atoms ( RCOR' )

Simple aldehydes and ketone

Multiple Choice

Is this an aldehyde or a ketone?

• aldehyde

• ketone

Multiple Choice

Is this an aldehyde or a ketone?

• aldehyde

• ketone

Naming Aldehydes

• Find the longest chain

• Change the ending to -al

• Do we need a number?

• No! aldehydes are always #1 (terminal)

• If there is a double bond, change the ending to --enal and use a number

Naming this aldehyde

1. Longest chain 6 carbons (hexanal)

2. Substituents (two methyls 3,4)

3. Full name: 3,4-dimethylhexanal

Multiple Choice

Which one is ethanal?

Multiple Choice

Which one is propanal?

Multiple Choice

Which one is 3-methylbutanal?

Multiple Choice

Name this

• 4-isopropyl pentanal

• 2-isopropyl pentanal

• 2-propyl-3-methylbutanal

Unsaturated

• Aldehyde is still #1

• Give the number where the double bond starts

• -ENal

• Include any substituents

Multiple Choice

Which one is 3-pentenal?

Multiple Choice

Which one is 3-butenal

Multiple Choice

Name this

• 2-methyl-1-butanal

• 3-methyl-3-butanal

• 1-aldo-3-butene

Poll

Which best describes you...

• I can identify an aldehyde and a ketone

• I can name an aldehyde with only single bonds

• I can name an aldehyde with double bonds

• I need more practice on all three