Naming Alkanes

Name, draw, and construct structural models of alkanes Include: branched alkanes, structural isomers Additional KEY Terms alkyl group substituent

C - C - C Methane CH4 Alkanes · distinguished by C-C single covalent bonds · general formula Cn H2n+2 · considered saturated (all single bonds) Propane C3H8 C - C - C H Methane CH4

A carbon branch (substituent) off the parent chain is called an Alkyl group. The alkyl groups follow the same naming system but end in "yl”. C - C - C - C - C - C C Formula Name –CH3 methyl –C2H5 or –CH2CH3 ethyl –C3H7 or –CH2CH2CH3 propyl Methyl group attached to a hexane parent chain.

C C - C - C - C - C - C Find the longest continuous chain of carbons. This is the parent chain. 2. Branches - Number the carbons of the parent chain from the end that gives the lowest number to the first branch: Ethyl branch attached to a hexane chain: C 6 1 5 2 C - C - C - C C - C - 4 3 3 4 5 2 6 1

3. Name each alkyl group including the number of the parent carbon it is attached to showing position. 4. Names are all ONE word. Hyphens used to separate numbers from words. C 1 3-ethylhexane 2 C - C - C - C - C - C 3ethylhexane 3 4 5 6

Draw the structural formula for 2-methylhexane. 1 2 3 4 5 6

2,4-dimethylpentane 1 2 3 4 5 CH3CH(CH3)CH2CH(CH3)CH3

Multiple alkyl groups require prefixes (di, tri) and parent numbers for each. The alkyls are named in alphabetical order. Commas are used to separate numbers. (5-ethyl-2,4-dimethyloctane) 4-ethyl-2-methylhexane C 6 C 5 C - C - C - C C - C - 4 3 2 1

C C C C C - C - C - C - C - C C - C - 5-ethyl-2,4-dimethyloctane 4 1 2 3 5 6 7 8 C

1 2 5 3 4 6 7 8 3,3,5trimethyloctane

3-ethyl-2,7-dimethyl-4-propyloctane

CH3CH2CH2CH(C2H5)CH2C(CH3)2CH3 7 6 5 4 3 2 1 4-ethyl-2,2-dimethylheptane

CAN YOU / HAVE YOU? Name, draw, and construct structural models of alkanes Include: branched alkanes, structural isomers Additional KEY Terms alkyl group substituent