1. • Characters:
- The oxygenated terpenes are the
principle odour carriers of the volatile oil.
- Have better solubility in dilute alcohol
than hydrocarbons.
- Have great stability against oxidizing
agents and resenifying influence.
2. • Oil rich in terpene hydrocarbons
rapid deterioration through oxidation and
resinification
develop a turpentine-like odour during storage.
3. • Removal of terpene hydrocarbons from the
oil, the oil left is called Terpeneless
volatile oil.
- More soluble in alcohol.
- More stable.
- Have much stronger odour.
4. • Methods of Preparation of Terpeneless
oil:
• 1- Fractional distillation under reduced
pressure
- hydrocarbons having boiling points lower than
oxygenated compounds and so distill first.
• 2- Column chromatography on silica gel.
- by eluting hydrocarbons with n-hexane and
oxygenated compounds with absolute alcohol.
5. • Terpeneless oils are higher in price than
natural oils.
• Advantages:
1- richer in oxygenated compounds.
2- have higher solubility in alcohol.
3- have much stronger odour.
4- do not deteriorate easily (more stable).
9. Methods used in Preparation of
Derivatives of Terpene Alcohols
• The most common derivatives are:
1- Dehydration Products.
2- Calcium chloride (CaCl2)addition products.
3- Esters:
examples of esters as:
a- Borates
b- Phthalates.
c- Benzoates.
d- Urethanes.
10. a- Borates
- Primary and secondary alcohols can readily
form borates.
- Tertiary alcohols do not react.
- Primary alcohols react more readily than
secondary alcohol
- So this method can be used for their
separation.
- Used for separation of primary, secondary and
tertiary alcohols in a mixture.
11. b- Phthalates
• Alcohol + phthalic anhydride monoester
derivative.
- This method is used for the separation of the
three alcohols.
12. - Primary Alcohols (in dil.benzene solutions)
Steam bath (100 °C)
Acid phthalates
(which are separated as Na salt of phthalate
acid ester from the secondary and tertiary
alcohols)
- Secondary Alcohols react less
readily need to be heated up to (120-130°C).
- Tertiary alcohols don’t react under these
conditions.
13. c- Urethanes
RN C O
Isocyanate Alcohol Urethanes
(carbamates)
+ ROH NHR C OR
O
N C O
+ ROH
NH COOR
Phenyl isocyanate Phenyl urethanes
Ex:
15. • Occurrence:
- The d-form present in oil of
Citronella (Cymbopogon
nardus).
- The l-form present in oil of
geranium and rose oil.
Citronellol
CH2OH
12
3
4
5 6
7
8
16. • Properties:
- optically active.
- colourless.
- Lighter than water.
- With typical rose-like odour.
• Isolation:
1- By fractional distillation
(fraction with boiling points 225-226°C).
17. 2- Preparation with phthalate derivative:
- heating with phthalic anhydride at 200°C and
formation of the (acid phthalate).
- The citronellol acid phthalate is purified with
alc. KOH and extraction with ether.
Phthalic
anhydride
+ R-OH
Acid
Phthalate
alc.KOH R-OH
+
Phthalate
K.salt
200°C
18. • Identification:
1- By preparation of the liquid acid phthalate
which yield crystalline silver salt “m.p. 125-
126°C”.
2- Upon oxidation with chromic acid it gives
citronellal (aldehyde form).
20. • Occurrence:
• Geraniol present in many oils as:
- Palmerosa,
- Geranium oil,
- Citronella oil and
- Rose oil.
• Nerol is present in oils of:
- petit grain (bitter orange),
- orange flower and
- bergamot.
21. • Properties:
- Both have rose-like odour.
- Lighter than water.
- The presence of two olefinic double bonds,
geraniol is highly reactive.
- Geraniol and Nerol are sensitive to mineral
acids and dehydrating agents.
22. • Geraniol Terpine hydrate
• Geraniol
• Geraniol Citral CHO
H
5% H2SO4
Dehydrating agent Diterpene or mix.of terpenoid
hydrocarbonsconc. H3PO4 or
heating with
K.bisulfate
oxidation
23. • Separation of Geraniol from Nerol
1- Only Geraniol forms crystalline additive with
CaCl2 insoluble in ether and benzene and
regenerated by warming with water.
• Geraniol Geraniol - CaCl2
2- Only Geraniol forms a crystalline acid
phthalate ester while Nerol doesn’t.
anhydrous CaCl2
Warm water (Crystalline complex)
Insoluble in ether and benzene
24. • Identification:
• Geraniol can be identified by determination of
the melting point of its derivatives.
1- diphenyl urethane (m.p. 82-83°C).
2- α-naphthol urethane (m.p. 47-48°C).
3- 3-nitrophthalate (m.p. 109°C).
• Nerol can be identified by its derivatives:
1- tetrabromide (m.p. 116-118°C).
2- diphenyl urethane (m.p. 52-53°C).
25. • Uses:
• It is used in manufacturing of perfumes, soap
and flavor industry.
26. • Occurrence:
• It is an unsaturated tertiary
alcohol.
• It occurs either free in d-
and l- isomers or in the
form of esters (usually
acetate).
(+)- Linalool
OH
27. • d- form present in oils of :
- rose wood, nutmeg, sweet orange and
coriander.
• l- form occurs in oils of:
- lavender, lemon, salvia and rose.
• Linalyl acetate occurs in oils of:
- Lavender and Bergamot.
28. • Isolation:
• By careful distillation of the saponified volatile
oil, since it doesn’t form any definite
crystalline derivatives.
29. • Action of Acids:
• 1- Because it is a tertiary alcohol, linalool
isomerizes to Geraniol by actions of acids.
• 2- It is easily oxidized by chromic acid or
formic acid (cold) to Citral
OH
H
CH2OH
CHO
Acid reagents Oxidation
Chromic acid
Geraniol
(+) - Linalool Citral
30. • 3- Upon esterification with glacial acetic acid
and acetic anhydride, linalool is converted in a
mixture of esters of geraniol, nerol and α-
terpeniol.
OH
(+) - Linalool
H
CH2OH
Geraniol
OH
H
CH2OH
+ +
Nerol α- terpeniol
glacial acetic acid
acetic anhydride
31. • 4- It converts to terpin hydrate with 5 % H2SO4
• 5- with halogen acids yields the corresponding
halides (e.g. Linalyl chloride and linalyl
bromide)
OH
(+) - Linalool
OH
OH
Terpin hydrate
5% H2SO4
hydration
32. • Identification:
• By preparation of the phenyl urethane and α-
naphthyl urethane derivatives.
• Uses:
• It is widely used in perfumes, cosmetics, soap
and flavor industries.
33. • Ocurrence:
- As esters of Benzoic and Cinnamic
acids in balsam Peru, balsam Tolu.
and
- ester of acetic acid (benzyl acetate)
in oil of Jasmin.
Aromatic Alcohols
Benzyl alcohol
CH2OH
34. • Isolation:
1- By fractional distillation of original or
saponified oil
2- or through additive derivatives with CaCl2
which regenerated by water.
• Uses:
- Perfumes, cosmetics and soap industry.
- Synthesis of flower oil (Jasmin).
40. • Uses:
- used in many pharmaceutical preparations.
- Counter-irritant on the skin and mucous
membranes.
- used as anti-septic in toothpastes and
mouthwashes.
- Flavoring agent for certain medicinal preparations,
candies and chewing gum.
41. 2- α- terpineol
• d- form of Neroli and bitter
orange.
• L-form in oil of camphor.
• crystalline compound.
• Uses:
- cosmetics.
- soap because of its lilac- like
odor.
OH
42. - It is a tertiary unsaturated cyclic alcohol.
- It easily loses water with some reagents.
OH
KHSO4
Formic ac
H3PO4
Dipentene
Terpinolene
Terpinolene α-Terpinene
α-Terpineol
43. Bicyclic Monoterpene Alcohols
Isoborneol(-)- BorneolName
Structure
- d- Borneol present in oil Nutmeg and Lavender.
- l- form in oil Citronella and Coriander
- Bornyl acetate present in pine needles oil.
Occurrence
- Crystalline with camphor-like odor.
- Readily oxidized to camphor.
Characters
-Scenting room sprays and soap.
-Bornyl esters are used in pharmaceutical preparations.
Uses
44. Isolation from Pine oil
Saponification of the oil (hydrolysis of esters)
Borneol crystals Liquid oil
Acid phthalate derivative of Borneol
Fractional distillation to remove hydrocarbons then cooling
46. Separation of Borneol from Camphor
Camphor Borneol acid phthalate ester
Phthalic anhydride
heat
O HO
Sodium salt
soluble in
water
NaHCO3
47. Sesquiterpene alcohols
α- Santalol
• Tricyclic sesquiterpene
alcohols.
• Viscous yellowish liquid.
• in oil of Sanadal wood
(Santalum album).
• The medicinal value of sandal
wood is due to Santalols.
CH2OH
55. • Color reactions:
1- Thymol + glacial acetic acid + dps H2SO4 + 1 dp.
HNO3 Deep bluish green color.
2- Thymol + conc H2SO4 + FeCl3 violet color.
3- Thymol + FeCl3 no color.
OH HO O
- H2O
56. • Identification:
• Derivatization to phenylurethane and
determination of the melting point.
• Uses:
• Local anesthetic in toothache.
• Mouth washes and oral preparations.
• Gastrointestinal disinfectant and anti-bacterial.
57. Monohydric phenolic ether
Anethole
• oils of Anise, fennel, star anise, F:
Umbelliferae.
• White crystalline.
• Sweet taste and odor.
• Uses:
• Flavoring mouthwashes, gargles,
food industry and beverages.
OCH3
59. Dihydric phenols and phenolic ethers
Eugenol
• oil of Clove and Cinnamon.
• Yellow oil.
• Clove odor.
• burning spicy taste.
• isolated by 3-5% KOH.
• Identified by:
1- + FeCl3 blue color.
OH
OCH3
60. • Uses:
- Local anesthetic in toothache.
- Flavoring agent in food, pharmaceutical
preparations, perfumes and soap.
- manufacture of Vanillin.
OH
OCH3
OH
OCH3
OAc
OCH3
OAc
OCH3
CHO
OH
OCH3
CHO
Eugenol
Vanillin
Isoeugenol
61. Tetrahydric phenolic ethers
Apiole (Parsley camphor)
• in parsley seed oil.
• Long colorless needles with faint
parsley odor.
• isolated by cooling at low
temperature then recrystallization
from alcohol.
O
O
OCH3
H3CO
