Alkanes and Nomenclature
By James Ashenhurst
Table of Functional Group Priorities for Nomenclature
Last updated: March 21st, 2019
Here’s a little nomenclature dilemma.
Let’s say you’re trying to name a molecule. You’re familiar with the familiar naming suffixes like -ol, -ene, -ane, -oic acid and so on. But then you come across a molecule which has multiple functional groups.
What do you do? What suffix do you give the molecule?
We need some kind of priority system for nomenclature. And so, IUPAC has developed one. If you have a molecule with, say, a carboxylic acid and a ketone you consult the table. The functional group with the highest priority will be the one which gives its suffix to the name of the molecule. So in example #1 above, the suffix of the molecule will be “-oic acid” , not “-one”, because carboxylic acids are given higher priority. However, if a ketone is present with an alcohol (example 3) then we will use the suffix, “-one” because ketones have a higher priority for nomenclature than alcohols.
[You might ask: what is this based on? It’s an arbitrary agreement by IUPAC [source], although note that there is some correlation between the oxidation state of the carbon and the priority (more oxidized groups tend to be higher priority). However this really is an example of something you have to either look up , memorize, or have a computer do for you. It’s not conceptual. ]
Here it is: Table of Functional Group Priorities For Nomenclature
Here are some examples of applying the order of functional group priorities to solve nomenclature problems. The highest ranked functional group becomes the suffix – it’s highlighted in red.
This covers most of the functional groups you’ll meet in Org1/Org2, if you run into a thioketone or some other bizarre entity, you’ll probably want to see Reusch or Wikipedia.
Related Posts:
00 General Chemistry Review
- Gen Chem and Organic Chem: How are they different?
- How Gen Chem Relates to Organic Chem, Pt. 1 - The Atom
- From Gen Chem to Organic Chem, Pt. 2 - Electrons and Orbitals
- From Gen Chem to Organic Chem, Pt. 3 - Effective Nuclear Charge
- From Gen Chem to Organic Chem, Pt. 4 - Chemical Bonding
- From Gen Chem to Organic Chem, Pt. 5 - Understanding Periodic Trends
- From Gen Chem to Org Chem, Pt. 6 - Lewis Structures, A Parable
- From Gen Chem to Org Chem, Pt. 7 - Lewis Structures
- From Gen Chem to Org Chem, Pt. 8 - Ionic and Covalent Bonding
- From Gen Chem to Org Chem, Pt. 9 - Acids and Bases
- From Gen Chem to Organic Chem, Pt. 10 - Hess' Law
- From Gen Chem to Organic Chem, Pt. 11 - The Second Law
- From Gen Chem to Org Chem Pt. 12 - Kinetics
- From Gen Chem to Organic Chem, Pt. 13 - Equilibria
- From Gen Chem to Organic Chem, Part 14: Wrapup
01 Bonding, Structure, and Resonance
- How Concepts Build Up In Org 1 ("The Pyramid")
- Review of Atomic Orbitals for Organic Chemistry
- How Do We Know Methane Is Tetrahedral?
- Hybrid Orbitals
- A Hybridization Shortcut
- Hybridization And Bond Strengths
- Sigma bonds come in six varieties: Pi bonds come in one
- A Key Skill: How to Calculate Formal Charge
- Partial Charges Give Clues About Electron Flow
- The Four Intermolecular Forces and How They Affect Boiling Points
- 3 Trends That Affect Boiling Points
- How To Use Electronegativity To Determine Electron Density (and why NOT to trust formal charge)
- Introduction to Resonance
- How To Use Curved Arrows To Interchange Resonance Forms
- Evaluating Resonance Forms (1) - The Rule of Least Charges
- Evaluating Resonance Forms (2): Applying Electronegativity
- Evaluating Resonance Forms: Factors That Stabilize Negative Charges
- Evaluating Resonance Forms (4): Positive Charges
- Exploring Resonance: Pi-Donation
- Exploring Resonance: Pi-acceptors
- In Summary: Resonance
- Drawing Resonance Structures: 3 Common Mistakes To Avoid
- How to apply electronegativity and resonance to understand reactivity
02 Acid Base Reactions
- Introduction to Acid-Base Reactions
- Walkthrough of Acid Base Reactions (1)
- Walkthrough of Acid Base Reactions (2): Basicity
- Walkthrough of Acid-Base Reactions (3) - Acidity Trends
- Five Key Factors That Influence Acidity
- Walkthrough of Acid-Base reactions (4) - pKa
- How to Use a pKa Table
- The pKa Table Is Your Friend
- A Handy Rule of Thumb for Acid-Base Reactions
- Acid Base Reactions Are Fast
- Putting Acidity In Perspective
- Acid Base Reactions: What's the Point?
03 Alkanes and Nomenclature
- Summary Sheet - Alkane Nomenclature
- Meet the (Most Important) Functional Groups
- Condensed Formulas: Deciphering What the Brackets Mean
- Hidden Hydrogens, Hidden Lone Pairs, Hidden Counterions
- Don't Be Futyl, Learn The Butyls
- Primary, Secondary, Tertiary, Quaternary In Organic Chemistry
- Branching, and Its Affect On Melting and Boiling Points
- The Many, Many Ways of Drawing Butane
- Common Mistakes: Drawing Tetrahedral Carbons
- Common Mistakes in Organic Chemistry: Pentavalent Carbon
- Table of Functional Group Priorities for Nomenclature
- Organic Chemistry IUPAC Nomenclature Demystified With A Simple Puzzle Piece Approach
04 Conformations and Cycloalkanes
- Conformations
- Newman Projections
- Putting the Newman into ACTION
- Introduction to Cycloalkanes (1)
- Cis And Trans Cycloalkanes
- Cycloalkanes - How To Calculate Ring Strain
- Cycloalkanes - Ring Strain In Cyclopropane And Cyclobutane
- Ring Strain in Cyclopentane and Cyclohexane
- An Aerial Tour Of The Cyclohexane Chair
- How To Draw A Cyclohexane Chair
- The Cyclohexane Chair Flip
- The Cyclohexane Chair Flip - Energy Diagram
- Substituted Cyclohexanes - Equatorial vs Axial
- Substituted Cyclohexanes: "A Values"
- The Ups and Downs of Cyclohexanes
- Which Cyclohexane Chair Is Of Lower Energy?
- Fused Rings
- Bridged Bicyclic Rings (And How To Name Them)
- Bredt's Rule (And Summary of Cycloalkanes)
05 A Primer On Organic Reactions
- The Most Important Question To Ask When Learning a New Reaction
- The 4 Major Classes of Reactions in Org 1
- Learning New Reactions: How Do The Electrons Move?
- How (and why) electrons flow
- The Third Most Important Question to Ask When Learning A New Reaction
- 7 Factors that stabilize negative charge in organic chemistry
- 7 Factors That Stabilize Positive Charge in Organic Chemistry
- Common Mistakes: Formal Charges Can Mislead
- Nucleophiles and Electrophiles
- Curved Arrows (for reactions)
- Curved Arrows (2): Initial Tails and Final Heads
- Nucleophilicity vs. Basicity
- The Three Classes of Nucleophiles
- What Makes A Good Nucleophile?
- Leaving Groups Are Nucleophiles Acting In Reverse
- What makes a good leaving group?
- 3 Factors That Stabilize Carbocations
- Three Factors that Destabilize Carbocations
- What's a Transition State?
- Hammond's Postulate
- Grossman's Rule
- Draw The Ugly Version First
- Learning Reactions: A Checklist (PDF)
- Introduction to Addition Reactions
- Introduction to Elimination Reactions
- Introduction to Free Radical Substitution Reactions
- Introduction to Oxidative Cleavage Reactions
06 Free Radical Reactions
- Bond Dissociation Energies = Homolytic Cleavage
- Free Radical Reactions
- 3 Factors That Stabilize Free Radicals
- What Factors Destabilize Free Radicals?
- Bond Strengths And Radical Stability
- Free Radical Initiation: Why Is "Light" Or "Heat" Required?
- Initiation, Propagation, Termination
- Isomers From Free Radical Reactions
- Selectivity In Free Radical Reactions
- Selectivity in Free Radical Reactions: Bromine vs. Chlorine
- Halogenation At Tiffany's
- Allylic Bromination
- Bonus Topic: Allylic Rearrangements
- In Summary: Free Radicals
- Synthesis (2) - Reactions of Alkanes
07 Stereochemistry and Chirality
- On Cats, Part 4: Enantiocats
- On Cats, Part 6: Stereocenters
- The Single Swap Rule
- Introduction to Assigning (R) and (S): The Cahn-Ingold-Prelog Rules
- Determining R/S (2) - The Method of Dots
- Types of Isomers: Constitutional Isomers, Stereoisomers, Enantiomers, and Diastereomers
- Enantiomers vs Diastereomers vs The Same? Two Methods For Solving Problems
- Assigning R/S To Newman Projections (And Converting Newman To Line Diagrams)
- The Meso Trap
- Optical Rotation, Optical Activity, and Specific Rotation
- Optical Purity and Enantiomeric Excess
- What's a Racemic Mixture?
- Chiral Allenes And Chiral Axes
08 Substitution Reactions
- Introduction to Nucleophilic Substitution Reactions
- Walkthrough of Substitution Reactions (1) - Introduction
- Two Types of Substitution Reactions
- The SN2 Mechanism
- Why the SN2 Reaction Is Powerful
- The SN1 Mechanism
- The Conjugate Acid Is A Better Leaving Group
- Comparing the SN1 and SN2 Reactions
- Polar Protic? Polar Aprotic? Nonpolar? All About Solvents
- Steric Hindrance is Like a Fat Goalie
- Common Blind Spot: Intramolecular Reactions
- The Conjugate Base is Always a Stronger Nucleophile
09 Elimination Reactions
- Walkthrough of Elimination Reactions (1)
- Elimination Reactions (2): Zaitsev's Rule
- Elimination Reactions Are Favored By Heat
- Two Types of Elimination Reactions
- The E1 Reaction
- The E2 Mechanism
- Comparing the E1 and E2 Reactions
- The E2 Reaction and Cyclohexane Rings
- Bulky Bases in Elimination Reactions
- Comparing the E1 and SN1 Reactions
- Elimination (E1) Reactions With Rearrangements
10 Rearrangements
11 SN1/SN2/E1/E2 Decision
12 Alkene Reactions
- Alkene Nomenclature: Cis and Trans and E and Z
- Addition Reactions: Elimination's Opposite
- Selective vs. Specific
- Addition Reactions: Regioselectivity
- Addition Reactions: Stereochemistry
- Markovnikov's Rule (1)
- Markovnikov's Rule (2) - Why It Works
- Curved Arrows and Addition Reactions
- Addition Pattern #1: The "Carbocation Pathway"
- Rearrangements in Alkene Addition Reactions
- Bromination of Alkenes - How Does It Work?
- Bromination of Alkenes: The Mechanism
- Alkene Addition Pattern #2: The "Three-Membered Ring" Pathway
- Hydroboration of Alkenes
- Hydroboration of Alkenes: The Mechanism
- Alkene Addition Pattern #3: The "Concerted" Pathway
- An Arrow-Pushing Dilemma In Concerted Reactions
- A Fourth Alkene Addition Pattern - Free Radical Addition
- Alkene Reactions: Ozonolysis
- Summary: Alkene Reaction Pathways
- Synthesis (4) - Reactions of Alkenes
13 Alkyne Reactions
- The 2 Most Important Reactions of Alkynes
- Partial Reduction of Alkynes To Obtain Cis or Trans Alkenes
- Hydroboration and Oxymercuration of Alkynes
- Alkyne Reaction Patterns - The Carbocation Pathway
- Alkyne Addition Reactions: The 3-Membered Ring Pathway
- Alkyne Addition Reactions - The "Concerted" Pathway
- Alkynes Via Elimination Reactions
- Alkynes Are A Blank Canvas
- Synthesis (5) - Reactions of Alkynes
14 Alcohols, Epoxides and Ethers
- Alcohols (1) - Nomenclature and Properties
- How To Make Alcohols More Reactive
- Alcohols (3) - Acidity and Basicity
- The Williamson Ether Synthesis
- Williamson Ether Synthesis: Planning
- Synthesis of Ethers (2) - Back To The Future
- Ether Synthesis Via Alcohols And Acid
- Cleavage Of Ethers With Acid
- Epoxides - The Outlier Of The Ether Family
- Opening Of Epoxide With Base
- Opening of Epoxides With Acid
- Making Alkyl Halides From Alcohols
- Tosylates And Mesylates
- PBr3 and SOCl2
- Elimination Reactions of Alcohols
- Elimination of Alcohols To Alkenes With POCl3
- Alcohol Oxidation: "Strong" and "Weak" Oxidants
- Demystifying Alcohol Oxidations
- Intramolecular Reactions of Alcohols and Ethers
- Protecting Groups For Alcohols
- Thiols And Thioethers
- Calculating the oxidation state of a carbon
- Oxidation and Reduction in Organic Chemistry
- Oxidation Ladders
- SOCl2 and the SNi Mechanism
- Synthesis (6) - Reactions of Alcohols
15 Organometallics
- What's An Organometallic?
- Synthesis of Grignard and Organolithium Reagents
- Organometallics Are Strong Bases
- Reactions of Grignard Reagents
- Protecting Groups In Grignard Reactions
- Synthesis Using Grignard Reagents (1)
- Grignard Reactions And Synthesis (2)
- Gilman Reagents (Organocuprates): How They're Made
- Gilman Reagents (Organocuprates): What They're Used For
- Common Mistakes with Carbonyls: Carboxylic Acids... Are Acids!
- The Heck, Suzuki, and Olefin Metathesis Reactions (And Why They Don't Belong In Most Introductory Organic Chemistry Courses)
- Reaction Map: Reactions of Organometallics
16 Spectroscopy
- Degrees of Unsaturation (Index of Hydrogen Deficiency)
- How Bleach Works: Understanding Colors From Nature
- Introduction To UV-Vis Spectroscopy
- UV-Vis Spectroscopy: Absorbance of Carbonyls
- UV-Vis Spectroscopy: Some Practice Questions
- Bond Vibrations, IR Spectroscopy, and the "Ball and Spring" Model
- Infrared Spectroscopy: A Quick Primer On Interpreting Spectra
- IR Spectroscopy: Some Simple Practice Problems
- Homotopic, Enantiotopic, Diastereotopic
- Liquid Gold: Pheromones In Doe Urine
- Natural Product Isolation (1) - Extraction
- Natural Product Isolation (2) - Purification of Crude Mixtures Overview
- Structure Determination Case Study: Deer Tarsal Gland Pheromone
17 Dienes and MO Theory
- What To Expect In Organic Chemistry 2
- How Concepts Build Up In Org 2
- Are these molecules conjugated?
- Conjugation and Resonance
- Molecular Orbital Diagram For A Simple Pi Bond - Bonding And Antibonding
- Molecular Orbitals of The Allyl Cation, Allyl Radical, and Allyl Anion
- Pi Molecular Orbitals of Butadiene
- Reactions of Dienes: 1,2 and 1,4 Addition
- Thermodynamic and Kinetic Control
- More On 1,2 and 1,4 Additions To Dienes
- s-cis and s-trans
- The Diels-Alder Reaction
- Cyclic Dienes and Dienophiles in the Diels-Alder Reaction
- Stereochemistry of the Diels-Alder Reaction
- Exo vs Endo Products In The Diels Alder: How To Tell Them Apart
- Molecular Orbitals in the Diels Alder Reaction
- Why Are Endo vs Exo Products Favored in the Diels-Alder Reaction?
- Diels-Alder Reaction: Kinetic and Thermodynamic Control
- The Retro Diels-Alder Reaction
- Regiochemistry In The Diels-Alder Reaction
18 Aromaticity
19 Reactions of Aromatic Molecules
- Electrophilic Aromatic Substitution: Introduction
- Activating and Deactivating Groups In Electrophilic Aromatic Substitution
- Electrophilic Aromatic Substitution - The Mechanism
- Ortho-, Para- and Meta- Directors in Electrophilic Aromatic Substitution
- Understanding Ortho, Para, and Meta Directors
- Why are halogens ortho- para- directors?
- Disubstituted Benzenes: The Strongest Electron-Donor "Wins"
- Electrophilic Aromatic Substitutions (1) - Halogenation
- Electrophilic Aromatic Substitutions (2) - Nitration and Sulfonation
- EAS Reactions (3) - Friedel-Crafts Acylation and Friedel-Crafts Alkylation
- Intramolecular Friedel-Crafts Reactions
- Nucleophilic Aromatic Substitution (NAS)
- Nucleophilic Aromatic Substitution (2) - The Benzyne Mechanism
- Reactions of Diazonium Salts: Sandmeyer and Related Reactions
- Reactions on the "Benzylic" Carbon: Bromination And Oxidation
- The Wolff-Kishner, Clemmensen, And Other Carbonyl Reductions
- More Reactions on the Aromatic Sidechain: Reduction of Nitro Groups and the Baeyer Villiger
- Aromatic Synthesis (1) - "Order Of Operations"
- Aromatic Synthesis (2) - Polarity Reversal
- Aromatic Synthesis (3) - Sulfonyl Blocking Groups
- Synthesis (7): Reaction Map of Benzene and Related Aromatic Compounds
20 Aldehydes and Ketones
- Weird Nomenclature In Carbonyl Chemistry
- The Simple Two-Step Pattern For Seven Key Reactions of Aldehydes and Ketones
- Wittig Reaction
- Imines and Enamines
- Acid Catalysis Of Carbonyl Addition Reactions: Too Much Of A Good Thing?
- On Acetals and Hemiacetals
- Carbonyl Chemistry: 10 Key Concepts (Part 1)
- Carbonyls: 10 key concepts (Part 2)
- Breaking Down Carbonyl Reaction Mechanisms: Anionic Nucleophiles (Part 1)
- Breaking Down Carbonyl Reaction Mechanisms: Reactions of Anionic Nucleophiles (Part 2)
21 Carboxylic Acid Derivatives
- Simplifying the reactions of carboxylic acid derivatives (part 1)
- Carbonyl Mechanisms: Neutral Nucleophiles, Part 1
- Carbonyl chemistry: Anionic versus Neutral Nucleophiles
- Proton Transfers Can Be Tricky
- Let's Talk About the [1,2] Elimination
- Carbonyl Chemistry: Learn Six Mechanisms For the Price Of One
- Summary Sheet #5 - 9 Key Mechanisms in Carbonyl Chemistry
- Summary Sheet #7 - 21 Carbonyl Mechanisms on 1 page
- How Reactions Are Like Music
- Making Music With Mechanisms
- The Magic Wand of Proton Transfer
- The Power of Acid Catalysis
22 Enols and Enolates
23 Amines
- Amides: Properties, Synthesis, and Nomenclature
- Basicity of Amines And pKaH
- 5 Factors That Affect Basicity of Amines
- The Mesomeric Effect And Aromatic Amines
- Nucleophilicity of Amines
- Alkylation of Amines (Sucks)
- Reductive Amination
- The Gabriel Synthesis
- Some Reactions of Azides
- The Hofmann Elimination
- The Hofmann and Curtius Rearrangements
- The Cope Elimination
- Protecting Groups for Amines - Carbamates
- Introduction to Peptide Synthesis
- The Strecker Synthesis of Amino Acids
24 Carbohydrates
- D and L Sugars
- What is Mutarotation?
- Reducing Sugars
- Pyranoses and Furanoses: Ring-Chain Tautomerism In Sugars
- The Big Damn Post Of Sugar Nomenclature
- The Haworth Projection
- Converting a Fischer Projection To A Haworth (And Vice Versa)
- Reactions of Sugars: Glycosylation and Protection
- The Ruff Degradation and Kiliani-Fischer Synthesis
25 Fun and Miscellaneous
- Organic Chemistry and the New MCAT
- A Gallery of Some Interesting Molecules From Nature
- The Organic Chemistry Behind "The Pill"
- Maybe they should call them, "Formal Wins" ?
- Introduction To Synthesis
- Organic Chemistry Is Shit
- The 8 Types of Arrows In Organic Chemistry, Explained
- The Most Annoying Exceptions in Org 1 (Part 1)
- The Most Annoying Exceptions in Org 1 (Part 2)
- Org 1 Review Quizzes
- Screw Organic Chemistry, I'm Just Going To Write About Cats
- On Cats, Part 1: Conformations and Configurations
- On Cats, Part 2: Cat Line Diagrams
- The Marriage May Be Bad, But the Divorce Still Costs Money
- Why Do Organic Chemists Use Kilocalories?
- What Holds The Nucleus Together?
- 9 Nomenclature Conventions To Know
Animation makes it all the more interesting !
thanks.
I think ether should be right after amines and alkane after nitro? some other website seem to say that, which one is correct?
With amines, the suffix “ine” is used, but when nitro groups or ethers are present, the alkane suffix is used: http://www.acdlabs.com/iupac/nomenclature/93/r93_322.htm
According to my view friend your thought is wrong because you should know that we write fg as prefix only when it has less priority and you can not use alkane as prefix. nitro group always remains in the form of prefix and ether vice versa. So fg having high priority is used in the form of suffix. Ether is not used as suffix so it has less priority than alkane. It will be after alkane and not after amine.
i think alkyne should come before alkene: it should be alkyne-alkene-alkane, decreasing unsaturation and increasing saturation…
Alkene does go first over alkyne, but I believe it is due to the alphanumeric priority of -ene over -yne and not based on the extent of saturation: http://www.chem.ucalgary.ca/courses/350/Carey5th/useful/nomen.html
You’re right Christopher. I found this from a book I am using to study for my DAT exam. I hope it helps
“Note: The group B functional groups (alkene and alkyne” are considered to have equal priority: in a molecule with both double and a triple bond, whichever is closer to the end of the chain determines the direction of numbering. In the case where each would have the same position number, the double bond takes the lower number. In the name, “ene” comes before “yne” because of alphabetization. See examples on the next page”
If Halogens have higher perioity than Nitro why the Nitro group is written after the Bromine
It’s just due to alphabetization. For example we would number 2-bromo 3-nitro butane based on the fact that bromine is higher up in (our) alphabet than nitro.
So does that apply to all the functional groups, in all cases?
It (alphabetization) only applies to substituents.
can anyone plz say what is d criteria for this table.????..
IUPAC.
well…but can u plz suggest me what r the criterias which IUPAC have applied???
I believe it is at least partially based on oxidation state, with higher oxidation state having higher priority. But that doesn’t explain why alkenes are higher priority than alkynes. Nomenclature is a human convention.
please give some example where carboxylic acid act as prefix .Will sulphonic acid be given more priority than carboxylic acid?
Can you please give example where carboxylic acid prefix ‘carboxy’ is used in nomenclature?
Can u please name this compound HOOC-CH²-CH²-CH²-CH(CH²-CH²-COOH)-CH²-CH²-CH²-COOH and HOOC-CH²-CH²-SO³H
Carboxy may be used when one of the chains attached to the root carboxylic acid also has the carboxylic acid functional group. E.g. 4-(Carboxymethylene)-2,5-heptadienedioic acid.
No because COOH is top on priority table
Why does alkyne have more priority ovr alkene? Because i have seen compounds where the least no: is given to alkynes ie., they hav been given most priority ovr alkene..for example, 6-chloro-4-ethyl-5-methylhept-5-en-1-yne
The yne might have been given priority in this case because the parent chain could be numbered in such a way to make one of the unsaturations C1, and it happened to be the yne and not the ene.
Tie goes to the ene, but this might not have been a tie.
According to: Principles of
Chemical Nomenclature
A GUIDE TO
IUPAC RECOMMENDATIONS, Edited by G.J. Leigh
Page 80-81:
If double and triple bonds are present in a structure, they are considered together
when assigning lowest locants. Only when this does not allow a resolution do double bonds receive the lowest locants.
In a name, the ending -ene is cited before -yne, but
with elision of the final ‘e’.
Examples
12. HCC-CH=CH-CH3 pent-3-en-l-yne
13. HCECCH=CH2 but-l-en-3-yne
Since ethers are “substituent-only” (named only by prefix), are peroxides prefix-only as well? What about epoxides? (I think that’s a little less clear, eg. oxirane.)
How would a peroxyacid RC(=O)OOH (“peracid”) or a perester RC(=O)OOR’ be handled?
I’m guessing a carbonate ROC(=O)OR’ takes priority over an ester RC(=O)OR’ ?
where would the halogens be in this table?
under the alkyl halide section, 2nd to last priority just above nitro.
Halogens come down at the rock botoom. They are not used as suffixes. Only Prefixes
Other websites show ethers as having higher priority than alkenes
http://www.chem.ucalgary.ca/courses/351/orgnom/functional/func.html
http://academics.keene.edu/rblatchly/OrgoCommon/hand/functgrps/Nomenclature.html
I agree, I think that ethers should be higher priority than alkanes. In the case of CH3OCH2CH3Ito should be named as ethyl methyl ether.
Thanks a lot! That really helped! :)
i have a doubt.suppose there’s a compound containing both alkene and alkyne functional groups. what gets higher preference?
Alkene, according to IUPAC.
If the carbon chain contains both the double and triple bond and they are both on the terminal carbons, then prioritization is given to the double bond. But if both double and triple bond are not on the terminal carbons, prioritization is given to the triple bond. These are called enynes.
Hey, in the 2nd example why do they use both the siffix and the prefix of nitromethane?
The alkane (” -ane “) has a higher priority than the nitro group, so the nitro group will not be used to a suffix.
Respected sir,
I have a doubt which may be small for you , but it brings more confusion if sulphonic acid and carboxylic acid are given which should be given priority first sir . sir please answer me and please give me a explanation.
Thanking you sir!
Carboxylic acid, according to this: http://www.acdlabs.com/iupac/nomenclature/79/r79_905.htm and this http://www.acdlabs.com/iupac/nomenclature/79/r79_469.htm
thanks a lot for reply but can you please explain In words
i suppose sulphonic acid is given a greater priority than carboxylic acid
Yes it is.
Can someone PLEASE suggest a mnemonic to learn this table?
I should give prioirity to br or alcohol
Alcohol, like it says in the table.
add carbonitrile with nitrile
Why NO2 is not taken as principal functional group , since the compound which is more withdrawing is considered to be as more powerful functional group!! So why is it so????
in that case even halides are in the bottom
Very informative and well organised….
However it would be awesome if sulphonic acid and anhydrides could be added too :D
They’re pretty superior
Thanx though, this saved me a ton of time
where does benzene stand in priority table?
is it above bromine?
If multi functional groups are there in a compound, for which 1 we should give priority?
That is the whole point of this priority table.
The so-called “Table of Functional Group Priorities For Nomenclature” can be misleading. It is not in accordance with past (1979, 1993) or present (2013) IUPAC recommendations.
In what way? Can you be more specific?
For example, in what way is the table not in accordance with the listing here: http://www.acdlabs.com/iupac/nomenclature/93/r93_326.htm
and of the groups which are only prefixes
http://www.acdlabs.com/iupac/nomenclature/93/r93_322.htm
Is the above given priority table authentic??
See http://www.acdlabs.com/iupac/nomenclature/93/r93_326.htm and http://www.acdlabs.com/iupac/nomenclature/93/r93_317.htm
This table agrees with information on those pages, from IUPAC’s “Blue Book”.
Out of Sulphonic acid and carboxylic acid which would be given more priority?? Please tell the answer…i m little confused
Carboxylic acids. http://www.acdlabs.com/iupac/nomenclature/93/r93_326.htm
Carboxylic acid would be given more priority
Where so3h must be placed
Just below carboxylic acids. See http://www.acdlabs.com/iupac/nomenclature/93/r93_326.htm
yes, you are right
This is for a true or false question:
“Butanal” is another name for isobutanol.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
I am almost 100% certain this is false, but I just want to be sure that there is no way, or possible arrangement of the alcohol group (-OH) that can occur that would result in it being possible to name it like a aldehyde right?
It is false.
I think that the priority order of functional group is this :
1. -COOH
2. -SO3H
3. -COOR
4. -COX
5. -CONH2
6. -CN
7. -CHO
8. =C=O
9. -OH
10. -NH2
11. =C=C=
12. -C-=C-
where is – X in order
X stands for a halide group.
I think it is good to provide this type of chart to the student because this help them in their study
So Thanks!!!
???????????????????????
Where do epoxides fit into this list? Are they considered a substituant or a functional group?
In the ease of open chain compounds the secondary prefix is added just before the root word in the alphabetical order. why is it so?
James, again, thanks SO much for making OChem.understable.
Happy New Year :).
This is wonderful! This website is so useful!
Tq so much
Your priority table is very very wrong. I think you should go study some more before misleading others. Please correct them our just remove the page
Well everything is fine, but i think sulphonic acid is missing which should be placed just below carboxylic acid. Thanks
When alcohol is on high priority than numbering should begin from alcohol. eg.
CH3CH(OH)CH3.
IUPAC NAME – 2-PROPANOL
BUT why can’t be 1-methyl Ethanol
Because the longest chain is 3 carbons long.
I think alkyne should come before alkenes
What about so3H, group
Absolutely PERFECT table for the names of functional groups, this was just what I needed. Thanks so much!
Awesome, glad you found it useful David.