[jkulier]

Hi there,

I thought I had the hang of determining priority groups around a chiral center, but here's the problem (I have attached a picture of the cyclohexane involved):

Assigning priority groups to 1-C: 1 = 1st carbon ( attached to dimethylethyl); 2 = 2nd carbon (attached to a methyl); 3 = 6-C; 4 = Hydrogen. My TA confirmed that this is right.

Assigning priority groups to 2-C: (this is what I think) 1 = 1st carbon; 2 = 2nd carbon; 3 = 3rd carbon; 4 = Hydrogen. However, my TA said that the second priority would go to the 3rd carbon, and the third priority would go to the 2nd carbon.

Is my TA incorrect? If not, then please tell me why he is right?

Thank you very much in advance 

[Squirmy]

Your TA is correct.

You have to look for the first difference between the substituents starting from the chiral carbon. Three of the substituents are carbon, so you have to go one level further out. One is a CH₃, one is a CH₂-C, one is a CH-C₂.

[jkulier]

I'm so sorry, but I don't quite follow. Would you mind being a bit clearer?

[jkulier]

Nevermind, I now understand the problem. Thank you again =)