The configuration about each double bond in these representations is cis.
Even though it lacks a chiral core, the trans isomer is chiral.
Because the alkene cannot be planar while the rest of the carbons in the bicyclic system span the rings, this double bond configuration causes significant strain.
Terpenes: demonstrate a key feature of biological systems' molecular logic.
In the laboratory, chemists apply the same principles, but their methods lack the accuracy and selectivity of enzyme-catalyzed reactions in live systems.
Head-to-tail bonds between isoprene units are far more abundant in nature than head-to-head or tail-to-tail connections.
The carbon atoms of the geraniol skeleton are numbered 1 through 8 to assist you to identify the places of cross-linkage and ring formation.
This numbered system is intended to indicate crosslinking places in the remaining terpenes.
(a) structural formula and
(b) ball-and-stick model