Which nomenclature is not according to IUPAC system?
Br−CH2−CH=CH21−bromo prop−2−ene
In IUPAC system of nomenclature, preference is given to multiple bond than halogen substituent, so the correct name of
3 2 1Br−CH2−CH=CH21−bromo prop−2−ene
Priority is given to double bond than halogen.