For the alkene part, priority order is as follows.
Following rule 1, iodo group gets first priority on C₁.
Following rule 3, R¹ gets first priority on C₂.

The discussion so far concerns the enantiomers only on paper, but to separate them experimentally is altogether new ball game. The process of separating a racemic mixture into its component enantiomers is called resolution. Historically, Louis Pasteur had resolved tartaric acid by crystallization and then separating the enantiomers by tweezers on the basis of hemihedral faces. However, as Pasteur said “Chance favours the prepared mind”, he was indeed fortuitous in this case. As it happened, he prepared the solution of racemic tartaric acid below 23°C. Had the temperature been any higher, he would have got crystals having both the enantiomers i.e.; racemic crystals. If the enantiomers in racemic mixture crystallize out of solution as pure enantiomers, then the enantiomers are said to form a conglomerate. It is usually rare and also depends on temperature and therefore the process is mainly of historical interest only. Sometimes seeding by the optically pure crystals of one enantiomer causes it to preferentially come out of solution.

A method that can be used practically is based on the fact that enantiomers have same physical and chemical properties but not diastereomers. This process involves the conversion of an enantiomer to a diastereomer by treating with a chiral reagent. The diastereomers are then separated by the usual methods. The separated diastereomers are then treated with appropriate reagents to regenerate the original enantiomers. An example of this method is the resolution of a racemic mixture of chiral acids by treatment with an optically pure base (Figure 7).

Figure 7