Question

What are the rules to EZ configuration? (Entgegen-Zusammen)

Answer 1

Hint: The IUPAC chosen method of defining the absolute stereochemistry of double bonds in organic chemistry is the E–Z arrangement, also known as the E–Z convention. It's a cis–trans isomer extension that can be used to represent double bonds with two, three, or four substituents.

Complete answer:
\[\left( {4E,{\text{ }}6E} \right) - 2,6 - dimethyloct - 2,{\text{ }}4,{\text{ }}6 - triene\]
Justification:
There are three different types of \[C = C\] bonds to choose from. The left one cannot be used since both bonds on the left hand side have the same combined atomic mass, one methyl group.
Since the left hand side only has a methyl ethane group, while the right hand side has the same thing, the middle \[C = C\] bond can be used. Since they're on opposite sides, it'll be in \[E\] notation.
On the right hand side of the right \[C = C\] bond, there is only a methyl group; on the left hand side, there is a methyl group and a \[2 - methylpent - 2,{\text{ }}4 - ene{\text{ }}group\] . The methyl group on the right hand side and the \[2 - methylpent - 2,{\text{ }}4 - ene{\text{ }}group\] on the left hand side are both on opposite sides, resulting in an \[E\] notation.
\[2,6 - dimethyloct - 2,{\text{ }}4,{\text{ }}6 - triene\] is the complete formula (without EZ notation). The two methyl groups on the 2nd and 6th carbon atoms in the main carbon chain give rise to\[2,6 - dimethyl\] . The name Oct comes from the fact that the main carbon chain has eight carbon atoms. The \[C = C\] bonds on the 2nd, 4th, and 6th carbon atoms in the main carbon chain give rise to \[2,{\text{ }}4,{\text{ }}6 - triene.\]
The full name is \[\left( {4E,{\text{ }}6E} \right) - 2,6 - dimethyloct - 2,{\text{ }}4,{\text{ }}6 - triene\] since the \[C = C\] bonds on the 4th and 6th carbon atoms in the main carbon chain have \[E\] notations. The \[E\] notation on the 4th and 6th carbon atoms in the main carbon chain is shown by \[\left( {4E,{\text{ }}6E} \right).\]

Note:
A special form of E/Z isomerism in which each C of a C=C double bond has a non-hydrogen group and a hydrogen atom attached to it is known as cis-trans isomerism. The cis isomer is the Z isomer, with hydrogens on the same side of each carbon, and the trans isomer is the E isomer, with hydrogens on opposite sides of the double bond.