(a) How many stereoisomers are possible for 9, 10-dibromohexadecanoic acid?
(b) The addition of bromine to palmitoleic acid yields primarily one set of enantiomers, (±)-threo-9, 10-dibromohexadecanoic acid. The addition of bromine is an anti addition to the double bond (i.e., it apparently takes place through a bromonium ion intermediate).
Taking into account the cis stereochemistry of the double bond of palmitoleic acid and the stereochemistry of the bromine addition, write three-dimensional structures for the (±)-threo-9,10-dibromohexadecanoic acids.