[Mager]

I am not quite clear as to whether the C with the double bonded Carbon has priority over the carbon bound to a methyl group?  In specific, 4-terbutyl-6-methylcycloheptene.  Why does Carbon #6 take priority over Carbon # 2 when determining R & S configuration?

[Hunter2]

I think its because Carbon 2 is double bonded.

[Mager]

I assumed that it would be carbon 2 as well, due to the double bond.  However, this is incorrect as the assignment for the specific molecule is (4R,6R)(Z)-4-tertbutyl-6-methylcycloheptene.  My only reasoning would be that the C=C double has only a "phantom" C while the methyl group has an actual C.

[AWK]

This is rule -CH(CH3)- has priority in regard to -CH(C)-

[clarkstill]

I think the alkene has priority. Look at each atom in isolation, and consider what stuff each is bonded to. C2 and C6 are both bonded to 3 x C (since the double bond counts for 2) and 1 x H, so you need to look in more detail at the attached groups:

attached to C2:
2 x C bonded to 3 carbons (C1 is counted twice, and each time the double bond counts as two bonds to carbon)
1 x C bonded to 2 carbons
1 x H

C6:
2 x C bonded to 2 carbons
1 x C bonded to 1 carbon
1 x H

So C2 has priority. I'm not 100% whether C1 is counted twice or once, but even if it's only counted once the methine would still beat the methylenes attached to C6. I'm happy for someone to correct me though!

[AWK]

Both C(4) or C(6) have the first atom of unsubstituted double bond as second neighbourhood (C(2) or C(1), respectively). Hence it is sufficient to take into account only the first atom of this double bond for consideration (H-C-C).The second group from other side is H-C-CH₃ or H-C-C(CH₃)₃. And these groups have priorities over the first atom of the double bond.