Download Ch 12 Alcohols and Thiols

Ch 12 Aldehydes and Ketones
Naming and Properties
Carbonyl Functional Group
• oxygen video
Aldehydes
• Functional group is a carbonyl group bonded
to an end-standing Carbon (#1)
• Condensed structural formula is indicated as –
CHO (COH is alcohol)
Ketones
• Carbonyl group is bonded to a central carbon
of a parent alkane or a ring
Aldehyde Naming
CH3
CH3 – CH2 – CH – CH2 – CH2 – C – H
1. Find longest C-chain containing carbonyl group
2. Name: drop the alkane‘e’ replace with ‘-al’ :
hexanal
3. In aldehydes, carbonyl is always C#1 – no number
needed – implied in aldehyde name!
4. Locate/list other substituents: 4-methylhexanal
Ketone Naming –CO–
Cl
CH3 – CH – C – CH2 – CH2 – CH3
1. Find longest C-chain containing carbonyl group
2. Name: drop alkane ‘e’ replace with ‘-one’
hexanone
3. Number: Carbonyl gets lowest possible number 3hexanone ( longer ketones need location number for
carbonyl)
4. Locate/list other substituents in front
2-chloro-3-hexanone
Complex molecules with
everything…..
• Use substituent name carbonyl (list alpha
under C)
Properties of Aldehydes & Ketones
• intermolecular forces of Carbonyls
1. Dipoles
2. Van der Waals – depending on Carbon chain
length
• Length of Carbon chain
• C1-C2 gas, C3 -C10: liquid, C11 and higher: solids
Melting and Boiling Points
• Aldehydes/ketones have BP between alkanes
and alcohols, close to ethers
• Intermolecular forces: Dipoles and Van-der-Waals,
but no H-Bonds with each other!!!!
Solubility
• Aldehydes and ketones with 4 or less carbons are
very soluble in water
• Carbonyl can H-bond with water
Rx of Aldehydes and Ketones
Oxidation of Aldehydes
• Aldehydes can be oxidized
• Visible as addition of Oxygen
aldehyde
carboxylic acid
Oxidation of Ketones
• Ketones cannot be oxidized!!!
• No H that can be removed
• No O can be added
Benedict’s Test
•
[O]
+ Cu2+ +O2 →
Glucose
+ Cu2O
Gluconic Acid
Sequential Oxidation of Carbon
Compounds
Purpose: gradual release of chemical bond energy
that can be captured (ATP) instead of a quick
combustion that produces mostly heat, light
(useless for the body)
alkane→ 1° alcohol → aldehyde→carboxylate→ CO2
alkane →2o alcohol →ketone → Ø
Branched alkane → 3o alcohol → Ø
• agains the grain