Question

In IUPAC nomenclature, while numbering, should double bond get highest priority or substituent?

Answer 1

Answer:

If four different groups are attached to the carbons of the double bond, you need to use the E/Z nomenclature convention.

In the E/Z system of classification the atoms attached to each carbon of a double bond are assigned a priority based on atomic number.

Higher atomic number atoms are assigned a higher priority.

Answer 2

Answer:

double bond should get highest priority than substituent