Number the Carbons Start at the end closest to the first attached group. If two substituents are equidistant,look for the next closest group. CH3 3 CH3 4 5 H3C-CH-CH-CH2一CH2一CH-CH 2 CH2CH: 67 Chapter 3 8Chapter 3 8 Number the Carbons • Start at the end closest to the first attached group. • If two substituents are equidistant, look for the next closest group. 1 2 3 4 5 6 7 H3 C CH CH3 CH CH2 CH3 CH2 CH2 CH CH3 CH3 =>