Common Names of Organic Molecules II Quiz

Answer: eugenol

Eugenol is the major component of clove oil. Clove oil is a mild local anaesthetic and used to be used by dentists to rub onto the teeth of people suffering from toothache. Its most common use now is in the perfume/fragrance industry.

Answer: vanillin

Vanillin is derived commercially from eugenol (see question 1 above), although it can be extracted naturally from the cured, unripe fruit of the plant Vanilla planifolia. If you look up the structures, you will see that vanillin and eugenol differ only in the one substituent on the benzene ring, so it is fairly easy chemically to convert the latter to the former.
Vanillin is used as a flavouring agent in confectionery, food and beverages and also in the perfume industry.

Answer: geraniol

Geraniol has a beautiful rose fragrance and is obtained from roses and geraniums (not hard to see where it gets its name!). Its major use is in perfumery. Geraniol is an example of a terpene (see question 10 of my first "Common Names of Organic Molecules" quiz).

Answer: menthol

As anyone who has used a nasal inhaler or cough drops for their cold will know, menthol has a lovely fresh, minty scent. It is derived from peppermint oil and is commonly used in pharmaceutical preparations to ease nasal congestion. It is also used in liqueurs and the perfume industry.

Answer: citronellol

Citronellol and geraniol have very similar structures - it's amazing what moving a couple of atoms around can do to the fragrance of a compound! Citronellol has a refreshing lemon scent and can be obtained from some rose and geranium oils and is also found in lemon-scented gum trees. Its main use is in perfumery.

Answer: linalool

Linalool (pronounced lin-uh-LOW-ol) has a delicate lavender fragrance. It can be obtained from sassafras, orange flower, bergamot or ylang-ylang. It is used in the perfume industry in place of French lavender oil.
Linalool and geraniol have very similar structures - the only difference is in the positioning of the alcohol group and one of the double bonds.

Answer: cinnamaldehyde

Cinnamaldehyde smells pleasantly like cinammon and is obtained from Ceylon and Chinese cinammon oils. It is used in the flavour and perfume industry.
The prefix "cinnam-" is used to denote the structural fragment of a benzene ring with the substituent of a 3-carbon unit containing a double bond. For example, 3-phenylpropenoic acid is known as cinammic acid.

Answer: isoamyl acetate

Isoamyl acetate is an ester with a lovely banana smell and can be obtained from pear or banana oil. It is used to give a pear flavour (go figure!) to mineral waters and syrups and is also used as a perfume for shoe polish.
"Isoamyl" is a common name for the isopentyl group. Isoamyl acetate could be made in a chemistry lab from acetic acid and isopentanol.

Answer: (-)-carvone

(-)-Carvone has a pleasant spearmint smell. The (-) in front of the name means that if a solution of (-)-carvone is placed in a polarimeter and polarised light is passed through the solution, then the solution will rotate the polarised light to the left (i.e., is levorotatory). Molecules that rotate polarised light to the right have a (+)- in front of their names (and are called dextrorotatory). Carvone has a (+) version too, which actually smells like caraway seed! This phenomenon is an example of enantiomerism. (+)- and (-)-carvone are enantiomers, which means that the two molecules are non superimposable mirror images of each other. Because of this, (+)- and (-)-carvone are actually two distinct molecules with different physical properties, despite having the same molecular formula. See any good organic chemistry text book if you'd like more information on this interesting branch of organic chemistry.

Answer: camphor

Camphor, obtained from the camphor tree, has a distinctive, pungent smell. It is used as an insect repellent, especially to deter moths from clothes.