1. Some Interesting Occurrences of Aldehydes
and Ketones in Natural Products
Organic Chemistry 212
Minh Anh Nguyen
minhanhnguyen@q.com

2. • Some naturally occurring aldehydes and ketones are
important in living systems. Some function as sex hormones;
others are used as flavorings and tasting. For example,
testosterone, the male sex hormone, and progesterone, a
hormone secreted by the ovaries that stimulates the growth of
cells in the uterine wall, both contain a ketone functional
group. In addition, aldehydes and ketones can be found in
foods, fragrance chemicals, and medicines. Some aldehydes are
responsible for very pleasant tastes and odors, such as vanillin
from vanilla beans, benzaldehyde from almonds,
cinnamaldehyde from cinnamon, etc. Formaldehyde is used to
preserve tissue. Acetaldehyde causes the unpleasant
“hangover” feeling that can result from consuming alcoholic
beverages. Ketones are also responsible for many well-known
odors such as those of garlic and camphor. Muscone or musk
oil is an ingredient in perfumes. The drug cortisone is a ketone
used to relieve individuals with rheumatism. Other uses for
ketones include industrial solvents such as acetone, which are
also used in every-day things like nail polish remover. In the
human body, the scent of acetone in saliva or urine can warn
of uncontrolled diabetes

3. Structures of Aldehydes and Ketones
• Both aldehydes and ketones contain a carbonyl
group. The carbonyl is a very polar group.
• Aldehydes have at least one H attached. Ketones
have two R’s attached to the carbonyl group.
Aldehydes
R H
O
Ketone
R R
O
sp2
Carbonyl
group
pentanal
O
O
2-pentanone

4. The differences between aldehydes and
ketones
• Aldehydes are less steric hindered than ketones.
• Aldehydes have fewer electron donating groups (EDG's)
which can stabilize an electron-poor area
• Aldehydes are readily oxidized to carboxylic acids, and
ketones resist oxidation. The oxidation of a primary
alcohol produces an aldehyde, and the oxidation of a
secondary alcohol yields a ketone.

6. Physical Properties of Aldehydes and
Ketones
• Aldehydes and Ketones have higher boiling points
than hydrocarbons, but have lower boiling points
than alcohols, because they have no H attached to
the O.
• Aldehydes and Ketones have strong odors, and are
often used as flavorings or scents.
• Small aldehydes are reasonably soluble in water.
Large aldehydes are less polar and dissolve more
readily in nonpolar organic solvents.

7. Aldehydes can be found in food
• Flavoring and or scent made from Aldehydes

9. Aldehydes can be found in food
Octanal is found both in orange oil
and orange juice. It's used
industrially to supply an orange,
especially to perfumes and
food preparations.

10. Aldehyde can be found in Human Body
and Fragrance Chemical
Retinal (retinaldehyde) is one of the many forms of vitamin A
and the chemical basis of Human and animal vision. It allows
certain microorganisms to convert light into metabolic energy.

11. Aldehyde can be found in Fragrance Chemical

12. Aldehydes can be found in medicine
• Formaldehyde is also an extremely
toxic substance; it has an irritating odor.
• Formaldehyde denatures proteins, rendering
them insoluble in water and resistant to
bacterial decay. It is used to preserve tissue.
• Acetaldehyde is
produced when one’s liver
metabolizes ethanol
(drinking alcohol) and causes
the symptoms of a hangover.

13. Ketones can be found in human body
• Testosterone is the male sex hormone. Progesterone is
the hormone produced by the female ovary after
ovulation.
• Aldosterone is secreted when blood sodium ion levels are
too low to cause the kidney to retain sodium ions. If
sodium levels are elevated, aldosterone is not secreted,
so that some sodium will be lost in the urine. Aldosterone
also controls swelling in the tissues.

14. Ketones can be found in Insects
• Pheromones are chemicals released by an organism into its environment
enabling it to communicate with other members of its own species. They are
released by both insects and mammals in many situations such as finding food
and mates, aggregating to take advantage of food resources, protecting sites of
ovipositor, and escaping predation, etc.
structure of the western pine beetle pheromone

17. Ketones can be found in one’s health
• In human bodies, Ketones are transported from the liver to other
tissues.
• Ketones are chemicals which appear
in the blood and urine when body fat is
being broken down for energy. Ketones
are formed when not enough food has
been eaten to provide the energy the
body needs.
• The concentration of ketones is less
than 1 mg/100 mL of blood. If the
ketones concentration rises to higher
levels, it is a warning of uncontrolled
diabetes. It is easy to detect in the
urine and odor can be noted on
the breath.

18. Ketone Diagram

19. Ketones can be found in food

22. Ketone can be found Medicine and Artificial
Sun Tan
• The drug cortisone is a ketone used to treat severe
allergies, arthritis, asthma, multiple sclerosis, and skin
conditions.

23. Acetone are widely used as industrial
solvents
• The simplest
Ketone is acetone
(propanone).
• It is used in
nail polish
remover, paints,
varnishes,
and resins.

24. Sources
• http://crab.rutgers.edu/~alroche/Ch18.pdf
• http://www.wiley.com/college/sc/klein/doc/Klein-ch20.pdf
• http://sydney.edu.au/science/chemistry/~george/aldehyde
s.html
• https://highered.mcgraw-
hill.com/sites/dl/free/0073511102/562156/ch13sample.pdf
• http://www2.fiu.edu/~herriott/ch16carbonyls.pdf
• http://highered.mcgraw-
hill.com/sites/dl/free/0073402621/825918/Chapter13.pdf
• http://www.scielo.br/scielo.php?pid=S0103-
50532007000600003&script=sci_arttext#fig01