Aldehydes Many of the naturally occurring molecules

Aldehydes and ketones
Organic Chemistry in Cosmetics: Flavors and Fragrance
Jolinette NkamdjeuMentor: Susan BontemsBackground Info:
Where aldehydes and ketone mostly found organically (Nature).
Different structures give different scents
Both Aldehyde and Ketones contain Carbonyl group
Ketones
Draw General structure
Describe Kind of odor (very strong, purgent smell)
Suffix “-one”
Ex. Acetone (structure) ; great polar aprotic solvent
Used in cosmetics such as nail polish remover
Most common Essential oil Ketone
Camphor ( Draw structure)
Found in rosemary, Camphor oil, Sage, Spike Lavender
Mentone ( Draw structure)
Odor description-
Peppermint; Cornmint (Menthol production comes from this through Crystallization). Also Predominant isomer
Compare L-R-Carvone to S-Carvone (draw structure)
R-Carvone Found in Spearmint
S-Carvone found in Caraway seed oil
Aldehydes
Draw general structure( carbonyl group is at terminal carbon)
Aldehydes —- can be oxidized into Carboxylic acid
Use Tollen’s Reagent Ag(NH3)2+
Ex of aldehydes associated with an odor
Methanal (characteristic pungent odor)
Ethanal (occurs in nature and produced)
Propanal (fruity odor)
Butanal (acrid smell)
Benzaldehyde (almond-like odor)
Cinnamaldehyde (cinnamon odor)
Tolualdehyde (4-Methylbenzaldehyde)
Many of the naturally occurring molecules containing aldehydes or ketone are chirals. Usually enantiomerically pure.
Oxidation/Reduction
Only Aldehydes can oxidize
Primary alcohol oxidize to and aldehyde then can oxidize to a carboxylic acid, as well as be reduced
Secondary alcohol can oxidize to a ketone, as well as be reduced
Reducing agent NaBH4
Reaction mechanism
Nucleophilic Addition
Reference:
https://www.fragrantica.com/notes/Aldehydes-165.htmlhttps://chem.libretexts.org/?title=Textbook_Maps/Organic_Chemistry/Supplemental_Modules_(Organic_Chemistry)/Aldehydes_and_Ketones/Properties_of_Aldehydes_%26_Ketones/Natural_Occurrence_of_Aldehydes_and_Ketoneshttps://bcachemistry.wordpress.com/2014/05/12/chemistry-of-fragrances-the-intricate-details-within-perfumes/