Ch 1 - Nomenclature Flashcards
What is the parent chain?
- longest carbon chain containing the highest-order functional group
- determines the root of the name
How do you number a carbon chain?
- the carbon numbered 1 will be the one closest to the highest priority functional group
- the highest priority functional group should have the lowest possible number; if all substituents have the same priority, make their numbers as low as possible
What are heteroatoms and how do they affect oxidation state?
- atoms beside carbon and hydrogen (like oxygen, nitrogen, phosphorous, and halogens)
- oxidation state increases with more bonds to heteroatoms and decreases with more bonds to hydrogen
How do bonds affect priority of functional groups?
the double bond takes precedence over the triple bond
What are substituents and how are they named?
- functional groups that are not part of the parent chain
- name is placed at the beginning of the compound name as a prefix followed by the name of the longest chain
What determines the suffix of the compound?
only the highest priority functional group and must be part of the parent chain
How do you assign a number to each substituent?
- pair the named substituents to the corresponding numbers in the parent chain
- multiple of the same type will get prefixes, even if they are on the same carbon
How to complete the name of a compound?
- names always begin with the names of the substituents in alphabetical order (ignore number and hyphenated prefix), with each preceded by its number
- numbers separated by commas and words with hyphens
- finish with the name of the backbone chain, including the suffix for the functional group of highest priority
What are the steps of IUPAC nomenclature?
- find the longest carbon chain
- number the chain
- name the substituents
- assign number to each substituent
- complete the name
What are hydrocarbons?
- compounds that contain only carbon and hydrogen atoms
What are alkanes and how are the named?
- simple hydrocarbon molecules with the formula CnH(2n+2)
- methane (1 carbon)
- ethane (2 carbon)
- propane (3 carbon)
- butane (4 carbon)
- from 5-12 they follow the prefix greek root: pentane, hexane, heptane, octain, nonane, decane, undecane, dodecane
What are alkenes and alkynes?
- end in -ene (double bond) and -yne (triple bond)
How are alcohols named?
- named by replacing the -e at the end of the name of the corresponding alkane with the suffix -ol
- chain numbered so that the carbon attacked to the OH group gets the lowest possible number, even when there is multiple bonds
What are 2 examples of alcohols with common names?
- ethyl alcohol = ethanol
- isopropyl alcohol = 2-propanol
What are diols?
- also termed glycols
- alcohols with 2 OH groups
- indicated with the suffix -diol
- when naming, must number each OH group
What is the difference between geminal diols and vicinal diols?
- Vicinial diols are in the Vicinity of each other, on adjacent carbons; Geminal diols - like Gemini twinss - are paired on the same carbon
- geminal: diols with OH groups on the same carbon (not commonly seen because they spontaneously dehydrate to produce carbonyl compounds with the functional group C=O
- vicinal: diols with OH groups on adjacent carbons
Why do alcohols take precedence over multiple bonds?
alcohols are more oxidized than multiple bonds, so they take priority in nomenclature and are indicated with the suffix -ol
What is a carbonyl group?
- a carbon double-bonded to an oxygen
What does chain-terminating mean?
- appear at the end of the parent chain
What are the differences and similarities between an aldehyde and a ketone?
- differ in the placement of the carbonyl group; aldehydes are chain-terminating and ketones are found in the middle of the carbon chain
- they both do not have any leaving groups connected to the carbonyl carbon, they are only connected to alkyl chains or H
What are aldehydes?
- have a carbonyl group found at the end of the carbon chain
- generally attached to carbon number 1 since terminal
What are 3 most common aldehydes and their IUPAC name?
- formaldehyde = methanal
- acetalaldehyde = ethanal
- propionaldehyde = propanal
What are ketones?
- contain a carbonyl group somewhere in the middle of the carbon chain
- always have to assign a number to the carbonyl carbon
How are ketones named?
- by replacing the -e in the name of the parent alkane with the suffix -one
- give the carbonyl the lowest possible number
How are aldehydes named?
- by replacing the -e of the parent alkane with the suffix -al
- when at position 1, do not need to include this number in the chemical name
What are the most common ketones and the IUPAC name?
- propanone = acetone
What has the highest precedence: double bond, alcohol, aldehyde?
aldehyde
When and how are prefixes used with aldehydes and ketones?
- in a more complex molecule with a higher priority that takes precedence over the carbonyl, name substituents using oxo-
- sometimes ketones use keto-
How are carbons named relative to the carbonyl groups of aldehydes and ketones?
- the carbon adjacent to the carbonyl carbon on both sides is the alpha
- then the beta, gamma, and delta
What are carboxylic acids?
- contain both a carbonyl group (C=O) and a hydroxyl group (-OH) on a terminal carbon
- terminal function group, therefore their carbon is usually position 1
How are carboxylic acids named?
- by replacing the -e at the end of the parent alkane with the suffix -oic acid
- highest priority therefore all other groups are named as substituents using prefixes
What are the 3 most common carboxylic acids and their IUPAC name?
- formic acid = methanoic acid
- acetic acid = ethanoic acid
- propionic acid = propanoic acid
What are esters?
- derivative of carboxylic acid
- the hydroxyl group (-OH) is replaced with an alkoxy group (-OR) where the R is a hydrocarbon chain
How are esters named?
- first term is the alkyl name of the esterfying group (R)
- second term is the name of the parent acid with -oate replaced -oic acid
- groups bonded directly to the ester oxygen are named as substituents and are not numbered
What are amides?
- derivative of caboxylic acid
- the hydroxyl group (-OH) is replaced with an amino group (nitrogen-containing group)
- amino nitrogen can be bonded to 0, 1, or 2 alkyl groups
How are amides named?
- first term is the amino group
- second term is the name of the parent acid with -amide replaced -oic acid
- substituents attached to the nitrogen atom are labeled with capital N- (not numbered), indicating that this group is bonded to the parent molecule via a nitrogen
What are anhydrides?
- derivative of carboxylic acid
- in the formation of an anhydride from 2 carboxylic acid molecules, one water molecule is removed
- many are cyclic
How are anhydrides named?
- replacing acid with anhydride in the name corresponding carboxylic acid if the anhydride is formed from only one type of carboxylic acid
- if the anhydride is not symmetrical, both carboxylic acids are named with the suffix -acid before anhydride is added to the name
What is the hierarchy of priority of the functional groups and their prefix/suffix?
- carboxylic acid (carboxy-, -oic acid)
- anhydride (alkanoloxycarboyl-, anhydride)
- ester (alkoxycarbonyl-, -oate)
- amide (amido-, -amide)
- aldehyde (oxo-, -al)
- ketone (oxo-, keto-, -one)
- alcohol (hydroxy-, -ol)
- alkene (alkenyl-, -ene)
- alkyne (alkynyl-, -yne)
- alkane (alkyl-, -ane_
