The instructions are reported at the bottom of the page
         
                    JME
                                    Editor courtesy of Peter Ertl, Novartis
 Save on Disk
 Useful commands in JSmol: 1) ALT +  mouse --> rotate in the plan (x y) 2) CTRL+ ALT + mouse --> move to the screen plan (x y) 3) mouse wheel --> zoom in and out 4) left click and drag mouse --> rotate in the three dimensions 
 
 Background Colour 
 
 Priority 
 
 
 
 
 
 
 
 Choose Chirality 
 Check Answer 
 Show all Chiral Carbons 
 
                
                     
 
            
                             
 
  
 
 
                        
Instructions:
1) to assign the priority, click on "Initialize".
2) click on the chiral carbon in JSMol and after click on "Chiral Carbon" button
3) repeat the step 2 for each atom directly linked to the Chiral Carbon to assign CIP Priority
4) orient the molecule the molecule properly, with the priority 4 group point away from you
5) assign the chirality, R or S, by clicking on the chiral carbon and after on the proper "R" or "S" button
6) check your answer by clicking on the "Check Chirality" button
Enantiomers
Sequence Rules
Sequence Rules
Assign the priority order to the susbtituents on the asymmetric carbon according to the Cahn-Ingold-Prelog rules.
- For every substituent, look at the first atom linked to the asymmetric carbon: the atom having the highest atomic number has the highest priority
 - If it is not possible to define all the priorities in this way, look at the second atom away form the double bond carbon atom, and so on, until a point of difference can be found.
 - The atoms having multiple bonds are equivalents to the same number of atoms linked by single bonds.
 

Correct Orientation of the Molecule
Correct Orientation of the Molecule
Orient the molecule with the lowest priority group (4) back, away from the observer.

Configuration Assignment
Configuration Assignment
Observe the sequence 1 ---> 2 ---> 3. If, in order to follow the correct order the rotation is:
       1) clockwise, the configuration is R
       2) counterclockwise, the configuration is  S

    
    
                                                            
                                                            

        
      