Page 197 - PG 504-theoretical notes-phyto-1-2024-2025..

Clinical pharmacy PharmD program Third level Phytochemistry-1 (PG-504)

Alicyclic Monoterpenes

1) Monocyclic

All monocyclic monoterpenoids are derived from

cyclohexane with additional CH3 and isopropyl side chains.

The typical saturated hydrocarbon is called O or m or p. menthane
The first degree of unsaturation gives a series P. menthenes the most important of which is
3
Δ -menthene which occurs naturally in pepperment oil
The second degree of unsaturation gives p-menthadienes.

Monocyclic monoterpenes can exist in some configurations which allow for existence of
isomers

Saturated hydrocarbons e.g. Menthane

Geometric isomers

T rans-form Cis-form

Strain isomers

Chair
Boat

First degree of unsaturation P-Menthene

7
1
6 2

3
5
4

8
10 9
1 2 4 4(8) 1(7)
∆ ∆ ∆ ∆ ∆

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