Nomenclature and Conformational Analysis Chapter 4: Alkanes Nomenclature and Conformational Analysis CH 4-1: Nomenclature of alkanes, alkyl halides (IUPAC) CH 4-2: Nomenclature of cycloalkanes (IUPAC) CH 4-3: Alkane conformations CH 4-4: Cycloalkane conformations

CH 4-1: Nomenclature of alkanes & alkyl halides Keys to naming organic compounds (IUPAC): 2-bromo-5-ethyl-3-methyl octane Know names of alkanes C1 – C10. Identify and name the “parent chain” Identify and name the “substituents” Know names of the alkyl substituents C1 – C5 and cycloalkyl substituents C3 – C6……

Alkyl Substituent Names A l k a n e ………………… A l k y l

“Ring” Substituents Cycloalkane = Cycloalkyl cyclohexyl cyclopentyl cyclopropyl

Halogen Substituents (replace –ine with –o) -fluoro -chloro -bromo -iodo

Be sure to review the nomenclature rules in your text! Example: Draw an accurate structure for: 2-bromo-3,3-dimethyl-5-propyl decane IUPAC “Rules”: 1. Always start with the “Parent Chain” (identify the number of carbons in the longest continuous carbon chain) 1 10

2. Locate the “substituents” (anything that branches off the parent chain). Name substituent group, and number its position relative to the end of the parent chain (use as low a number as possible). 2-bromo-3,3-dimethyl-5-propyl decane 3. If two or more substituents, then list alphabetically. (Note: di-, tri-, tetra-, and tert- prefixes are ignored in alphabetizing; iso- and cyclo- are not).

4. Draw the complete structure (if name is given) as Lewis structure or zig-zag. If you were given a structure then write the complete name of the compound. 2-bromo-3,3-dimethyl-5-propyl decane Line structure (zig-zag):

Summary: Organic Nomenclature IUPAC “Rules”: 1. Always start with the “Parent Chain” (the longest continuous carbon chain); name it. 2. Locate the “substituents” (anything that branches off the parent chain). Name substituent group and number its position relative to the end of the parent chain (use as low a number as possible). 3. If two or more substituents, list alphabetically. Note: di, tri, tetra and tert prefixes are ignored in alphabetizing; iso and cyclo are not. 4. Draw the complete structure (if name is given) as Lewis structure or zig-zag. If you were given a structure then write the complete name of the compound.