Page 29 - Pharmd general phytochemistry I-Final2024_LEUCTERS

As a general rule primary alcohols react more readily with acid
anhydrides, than secondary alcohols, and tertiary alcohols are not
appreciably affected:

• 1ry alc + Phthalic anhydride Steam bath Phthalic acid ester
dil. benzene

The acid esters can be extracted with sodium bicarbonate, and hydrolysis
regenerates the alcohols.

• 2ry alc + Phthalic anhydride 120-130°C Phthalic acid ester

• 3ry alc + Phthalic anhydride No ester
formation (but dehydration occurs).

Used for the separation of (or distinguish between) 1ry from 2ry and
3ry alcohols in a mixture.

3- Dehydration products:

Most 3ry alcohols are unstable and split off water, when reacted upon by
reagents generally employed in the preparation of alcohol derivatives.
Dehydration products may be useful for the identification of the 3ry alcohol.
- The dehydration process is sometimes used in the quantitative
determination of alcohols, as certain alcohols dehydrate quantitively
under special conditions ex. 3ry alcohols such as linalool, terpineol.

1- Acyclic monoterpene alcohols:

Citronellol

- Source:
Citronella oil (lemon grass).

- Oxidation to citronellal (aldehyde).

- Doesn’t form adduct with anhydrous CaCl2.

- Uses:
� Used in cosmetics, perfumes, soaps.
� It has antiseptic, bactericidal, deodorant and insecticide properties.

Citronella oil is used as a mosquito repellent in insect sprays, candles.

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