IUPAC Nomenclature of Organic Compounds In Chemistry, an organic compound is one containing carbon atoms. Carbon has 4 valance electrons and makes four bonds Carbon combines with many other carbon atoms making chains and rings which other atoms can be attached. There are a plethora of different organic compounds in our world. Naming Alkane Hydrocarbons C methane C-C ethane C-C-C propane C-C-C-C butane C-C-C-C-C pentane C-C-C-C-C-C hexane C-C-C-C-C-C-C heptane C-C-C-C-C-C-C-C octane C-C-C-C-C-C-C-C-C nonane C-C-C-C-C-C-C-C-C-C decane C-C-C-C-C-C-C-C-C-C-C undecane C-C-C-C-C-C-C-C-C-C-C-C dodecane Alkyl Groups Attached to Chain methyl ethyl propyl butyl CH3 CH2 CH3 CH2 CH2 CH3 CH2 CH2 CH2 CH3 Naming Alkanes- hydrocarbons with single bonds The longest chain is octane methyl The substituents are ethyl attachments ethyl 1 2 C 8 3 C 7 C 6 4 5 5 C C C C3 C C 4 too big Number the carbons on the longest chain so that substituents have the lowest numbers 6 2 1 C Name using alpha order for substituents Dashes between a number and a letter 4-ethyl -3-methyl octane start here C methyl methyl methyl C C C C3 C 4 C C C 5 6 2 3,3-dimethylhexane 1 Must use 3 twice because there are 2 methyl groups C4H10 has two structural isomers: Same formula but different structure CH3 CH3 C CH3 CH3 CH2 CH2 CH3 H The isomers have different connectivity and are different chemicals Try drawing a different isomer with four carbons There are no other isomers The alkane, C5H12 , has three structural isomers. Try to build three different molecules with 5 carbons and 12 hydrogens (using only single bonds), then draw it. C5H12 has the following three structural isomers: CH3 CH3 C CH3 CH3 CH3 CH3 C CH2 CH3 H CH3 CH2 CH2 CH2 CH3 Practice Questions Question 1: What is the correct IUPAC name? C C C C Question 1: What is the correct IUPAC name? C C Answer: butane C C Question 2: What is the correct IUPAC name? CH3 CH2 CH3 Question 2: What is the correct IUPAC name? CH3 CH2 Answer: propane CH3 What is the correct IUPAC name? C C C C C 2, 2-dimethylbutane C Question 4: What is the correct IUPAC name? CH3 CH3 C CH3 CH2 CH2 CH CH2 CH3 CH2 CH2 CH3 Question 4: What is the correct IUPAC name? CH3 CH3 C 3 CH2 CH CH2 CH3 CH3 CH2 3,3–dimethyl-5-ethyloctane 5 CH2 CH2 CH3 Draw the structural formula for 2-methylbutane 2 CH3 CH2 CH CH3 CH3 or CH3 CH3 CH CH2 CH3 2