Orgo 1 Study Guide
Introduction to Alkane Nomenclature
A. Determining the Priority of Functional
Groups.
What's in a name?
3-ethyl-5-(1-methylpropyl)-4,4-dimethylnonane
Too big a subject to cover on one sheet! This paper will focus on alkanes. Determining functional group priority will be the subject of a subsequent sheet.
suffix
http://masterorganicchemistry.com
D. Applying the Lowest Locator Rule
F. Dealing With Branched Substituents
(the IUPAC Way)
Number the chain from one end so as to provide the lowest locator possible for the first substituent.
Treat each branched substituent as its own naming problem.
Carbon #1 of the branched substituent will be where it meets the main chain.
2
1
3
4
5
6
6
7
7
5
2
4
1
3
B. Applying the Chain Length Rule the NUMBERS are called "locators" items in BLUE are called "substituents". the name in RED at the end is called the suffix.
9
7
8
6
5
3-methyl heptane
4
3
This also applies for subsequent substituents, if either direction would give the same number.
2
1
The purpose of this sheet is to demonstrate the rules by which alkanes are named.
4-ethyl-6-methylnonane
ORDER OF BUSINESS
A. Determine the priority of functional groups (not covered here since we're dealing with alkanes only)
B. Find the longest linear chain of your molecule, or the largest ring (whichever is greatest). This is the Chain length rule which defines both the "main chain" and also the suffix.
-tiebreaker: where more than one "path" along the molecule leads to the longest chain, the main chain is the one that contains the most substituents.
C. Identify the substituents along your main chain. Substituents are classified according to length of carbon chain and the suffix "yl" is attached.
D. Number your chain from one of the ends. The LOWEST LOCATOR RULE determines which end is chosen as carbon #1: "Number the chain such as to provide the lowest
possible
A. Determining the Priority of Functional
Groups.
What's in a name?
3-ethyl-5-(1-methylpropyl)-4,4-dimethylnonane
Too big a subject to cover on one sheet! This paper will focus on alkanes. Determining functional group priority will be the subject of a subsequent sheet.
suffix
http://masterorganicchemistry.com
D. Applying the Lowest Locator Rule
F. Dealing With Branched Substituents
(the IUPAC Way)
Number the chain from one end so as to provide the lowest locator possible for the first substituent.
Treat each branched substituent as its own naming problem.
Carbon #1 of the branched substituent will be where it meets the main chain.
2
1
3
4
5
6
6
7
7
5
2
4
1
3
B. Applying the Chain Length Rule the NUMBERS are called "locators" items in BLUE are called "substituents". the name in RED at the end is called the suffix.
9
7
8
6
5
3-methyl heptane
4
3
This also applies for subsequent substituents, if either direction would give the same number.
2
1
The purpose of this sheet is to demonstrate the rules by which alkanes are named.
4-ethyl-6-methylnonane
ORDER OF BUSINESS
A. Determine the priority of functional groups (not covered here since we're dealing with alkanes only)
B. Find the longest linear chain of your molecule, or the largest ring (whichever is greatest). This is the Chain length rule which defines both the "main chain" and also the suffix.
-tiebreaker: where more than one "path" along the molecule leads to the longest chain, the main chain is the one that contains the most substituents.
C. Identify the substituents along your main chain. Substituents are classified according to length of carbon chain and the suffix "yl" is attached.
D. Number your chain from one of the ends. The LOWEST LOCATOR RULE determines which end is chosen as carbon #1: "Number the chain such as to provide the lowest
possible