1. 25.9 Ketoses 13

2. Ketoses
Ketoses are carbohydrates that have a ketone carbonyl group in their open-chain form.
C-2 is usually the carbonyl carbon.

3. Examples H CH2OH O OH HO H CH2OH O OH HO H CH2OH O OH D-Ribulose
L-Xyulose
D-Fructose 14

4. 25.10 Deoxy Sugars 15

5. Deoxy Sugars
Often one or more of the carbons of a carbohydrate will lack an oxygen substituent. Such compounds are called deoxy sugars. 16

6. Examples CH O CH2OH H OH CH O CH3 HO H OH 2-Deoxy-D-ribose
6-Deoxy-L-mannose 16

7. 25.11 Amino Sugars 17

8. An amino sugar has one or more of its oxygens replaced by nitrogen.
Amino Sugars
An amino sugar has one or more of its oxygens replaced by nitrogen. 16

9. N-Acetyl-D-glucosamine
Example O OH NH HO
HOCH2 C
CH3
N-Acetyl-D-glucosamine 18

10. Example O OH HO
H3C
NH2
L-Daunosamine 18

11. 25.12 Branched-Chain Carbohydrates19

12. Branched-Chain Carbohydrates
Carbohydrates that don't have a continuous chain of carbon-carbon bonds are called branched-chain carbohydrates. 16

13. Examples CH O CH2OH H OH HO O OH HO H3C NH2 CH3 D-Apiose L-Vancosamine20