Hydroxy acids, also known as polycarboxylic acids, has two carboxylic groups, at least. They can also present one carboxylic group or a hydroxyl group with a ketone. The most common hydroxy acids used to make multicomponent complexes with cyclodextrin are: 1.citric acid, 2. tartaric acid, 3. glycolic acid, 4. oxalic acid.

1. -DEEPANSHU KUMAR YADAV
VTH SEMESTER [CBZ]

2. 1. Malic Acid
2. Tartaric Acid
3. Citric Acid
PREPARATION AND CHEMICAL REACTION OF
HYDROXY ACID

3. Malic acid can be prepared by the
following methods:
1. By the partial reduction of tartaric acid
2. From bromosuccinic acid
3. From maleic acid

4. 2. By the partial reduction of tartaric acid: Malic
acid can be prepared by the reduction of tartaric acid
with HI.
Red P
200℃

5. 3. From bromosuccinic acid: When bromosuccinic
acid is treated with moist silver oxide, malic acid is
obtained.

6. H2SO4
Pressure
3. From Maleic Acid

7. Chemical Reaction of Malic Acid
1. Action of heat
2. Oxidation with KMnO4
3. Reduction

8. Action of heat: Malic acid undergoes dehydration
on heating to form maleic anhydride.
HCL

9. Oxidation with KMnO4
On oxidation with KMnO4 malic acid forms
oxalacetic acid, which exits in keto-enol tautomerism.

10. Reduction
Malic acid reduces with HI to form succinic acid.

11. TARTARIC ACID

12. Preparation of tartaric acid
1. From glyoxal
2. From Kiliani-Fisher synthesis: Kiliani
3. From α, α'-dibromosuccnic acid

13. From Glyoxal
On treatment with hydrogen cyanide,
glyoxal produces glyoxal cynohydrin which
on hydrolysis gives tartaric acid.

14. From Kiliani-Fisher synthesis: Kiliani- Fisher synthesis is
one of the methods to increase no of carbons in compounds.
Tartaric acid can also be formed from glyceraldehydes.

15. From α, α'-dibromosuccnic acid
Both (±) and meso tartaric acids are prepared by boiling α, α'-
dibromosuccnic acid with moist silver oxide.

16. Chemical Reaction of Tartaric Acid
1. Oxidation
2. Reduction
3. Action of heat

17. Oxidation
With mild oxidizing agents tartaric acid yields tartonic acid
while with strong oxidizing agents, tartaric acid forms oxalic
acid.
Ag2O
4Ag CO2

18. Reduction
Tartaric acid with HI is reduced into malic acid
2

19. Action of heat: When tartaric acid is heated at
150ºC, it decomposes into tartaric anhydride.
On strong heating, it decomposes into pyruvic acid with
the evolution of CO2.
KHSO4

20. CITRIC ACID

21. From Glycerol
By Grimaux and Adam synthesis (1880)
1,2,3-hydroxy
propane
1,3-dichloro-
2-propenol
1,3-dichloro-
2-propanone
1,3- dichloro-2-cyno-
2-hydroxypropane
α-chloromethyl-α-hydroxypropionic
acid
β-cyno-α-cynomethyl-α-
hydroxypropionic acid
2-hydroxy-1,2,3-
tricarboxylic acid
HNO3

22. FROM CANE SUGAR
C12H22O11 + 3O2 2C6H8O7 + 3H2O
C6H12O6+3[O] C6H8O7 + 2H2O
Aspergillus niger
40℃
Cane Sugar
Citric acid

23. Chemical Reactions of Citric acid
1. Action of heat
2. Reduction

24. 1. Action of heat: On heating at 150 ºC, citric acid
undergoes dehydration as:
On heating with fuming sulphuric acid at 150 ºC, citric acid gives
acetone dicarboxylic acid.

25. 3. Reduction
In presence of hydrogen iodide citric acid reduced to
tricarballylic acid.
Reflux

26. With copper and sodium carbonate it forms
Benedict Solution
6Na+
Sodium Cupricitrate