Question

Question: Classify each terpene and terpenoid in Problem 31.26 (e.g., as a monoterpene, sesquiterpene, etc.).

Short answer

Answer

(a)Monoterpene

(b)Monoterpene

(c)Tetraterpene

(d)Tetraterpene

(e)Sesquiterpene

(f)Sesquiterpene

(g)Diterpene

(h)Triterpene

Step-by-step solution

Classification of Isoprene units

The isoprene units are classified into the following classes: monoterpene (two isoprene units), diterpene (four isoprene units), triterpene (three isoprene units), tetraterpene (eight isoprene units), and so on.

These all have different numbers of carbon atoms.

Isoprene units in each compound

a. There are 10 carbon atoms in the neral compound and two isoprene units. So, it is considered a monoterpene.

neral

b. In the carvone compound, there are 10 carbon atoms and two isoprene units. So, carvone is considered a monoterpene.

carvone

c. In the lycopene compound, there are 40 carbon atoms and eight isoprene units. So, it is considered a tetraterpene.

lycopene

d. In the $\beta -carotene$ compound, there are 40 carbon atoms and eight isoprene units. So, $\beta -carotene$ is considered a tetraterpene.

$\beta -carotene$

Isoprene units in each compound

e. In the patchouli alcohol compound, there are 15 carbon atoms and three isoprene units. So, patchouli alcohol is considered a sesquiterpene.

patchouli alcohol

f. In the periplanone B compound, there are 15 carbon atoms and three isoprene units. So, patchouli alcohol is considered a sesquiterpene.

periplanone B

g. In dextropimaric acid, there are 20 carbon atoms and four isoprene units. So, patchouli alcohol is considered a diterpene.

dextropimaric acid

h. In $\beta -amyrin$, there are 30 carbon atoms and three isoprene units. So, patchouli alcohol is considered a triterpene.

$\beta -amyrin$