2. Number the longest chain beginning with the end of the chain nearer the substituent(编号) 654321 765 CH3CH2CH2CH3CHCH3 CH3 CH2 CH2CH3 CHCH3 CH 3 CH 2 CHE Substituent(取代基)
2. Number the longest chain beginning with the end of the chain nearer the substituent.(编号） CH3 CH2 CH2 CH3 CHCH3 CH3 CH3 CH2 CH2 CH3 CHCH3 CH2 CH3 6 5 4 3 2 1 7 6 5 4 3 2 1 Substituent （取 代 基 ）
3. Use the numbers obtained by application of rule 2 to designate the location of substituent group (取代基定位) The parent name is placed last The substituent group name is placed first Numbers are separated from words by a hyphen
3. Use the numbers obtained by application of rule 2 to designate the location of substituent group. (取代基定位） • The parent name is placed last. • The substituent group name is placed first. • Numbers are separated from words by a hyphen
CH3 CHCH3 CH3CH2 CH3CHCH3 CH CH2 2 CH 2-Methylhexane 3-Methylheptane not 5-meth lhexane not 2-ethylhextane
CH3 CH2 CH2 CH3 CHCH3 CH3 CH3 CH2 CH2 CH3 CHCH3 CH2 CH3 6 5 4 3 2 1 7 6 5 4 3 2 1 2-Methylhexane 3-Methylheptane not 2-ethylhextane not 5-methylhexane
4 When two or more substituents are present, give each substituent a number corresponding to its location on the longest-chain CH3 CHCH2 CHCH2 CH3 CH3 CH CH3 4-Ethyl-2-methylhexane
4. When two or more substituents are present, give each substituent a number corresponding to its location on the longest-chain CH3 CHCH2 CHCH2 CH3 CH2 CH3 CH3 4-Ethyl-2-methylhexane
5. When two substituents are present on the same carbon atom, use that number twice CH3 CH3 CCH2 CH2 CH3 CH2 CH3 3-Ethyl-3-methylhexane Not 3-ethylmethylhexane
5. When two substituents are present on the same carbon atom, use that number twice CH3 CH2 CCH2 CH2 CH3 CH2 CH3 CH3 3-Ethyl-3-methylhexane Not 3-ethylmethylhexane