Longest Chain The number of carbons in the longest chain determines the base name: ethane,hexane.(Listed in Table 3.2, page 81.) If there are two possible chains with the same number of carbons,use the chain with the most substituents. H3C CH-CH2-CH3 CH3 H3C-CH2-C- CH CH2-CH2一CH3 CH3 Chapter 3 >
Chapter 3 6 Longest Chain • The number of carbons in the longest chain determines the base name: ethane, hexane. (Listed in Table 3.2, page 81.) • If there are two possible chains with the same number of carbons, use the chain with the most substituents. C CH3 CH2 CH3 CH CH2 CH2 CH3 CH CH2 CH3 H3C H3C =>
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 CH3,4, CH3 HC-CH-CH-CH2一CH2一CH-CH3 2 CH2CH3 67 Chapter 3
Chapter 3 7 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 =>
Name Alkyl Groups ·CH3,methyl ·CH3CH2,ethyl CH3 CH3一CH-CH2 ·CH3CH2CH2,n-propyl isobutyl CH3CH2CH2CH2-,n-butyl CH3 CH3-CH-CH3 CH3-CH-CH2-CH3 H;C-C-CH3 isopropyl sec-butyl tert-buty => Chapter 3 8
Chapter 3 8 Name Alkyl Groups • CH3 -, methyl • CH3CH2 -, ethyl • CH3CH2CH2 -, n-propyl • CH3CH2CH2CH2 -, n-butyl CH3 CH CH2 CH3 sec-butyl CH3 CH CH3 CH2 isobutyl CH3 CH CH3 isopropyl H3 C C CH3 CH3 tert-butyl =>
Propyl Groups HHH HH u-cccu HHH HHH n-propyl isopropyl A primary carbon A secondary carbon => Chapter 3 9
Chapter 3 9 Propyl Groups C H H H C H H C H H H n-propyl C H H H C H C H H H isopropyl H A primary carbon A secondary carbon =>
Butyl Groups HHHH HHH H HHHH HHHH n-butyl sec-butyl A primary carbon A secondary carbon => Chapter 3 10
Chapter 3 10 Butyl Groups C H H H C H C H H C H H H C H H H C H C H H H C H H n-butyl sec-butyl H H A primary carbon A secondary carbon =>