Chp. 3.3.pdf

📚 9/9/24, 11:48 AM IUPAC Naming System for Organic Compounds IUPAC Naming IUPAC (International Union of Pure and Applied Chemistry) is the organization responsible for our current organic chemistry...

📚 9/9/24, 11:48 AM IUPAC Naming System for Organic Compounds IUPAC Naming IUPAC (International Union of Pure and Applied Chemistry) is the organization responsible for our current organic chemistry naming system. What is a Substituent? 🤔 A substituent is any appendage dangling off of the molecule's parent chain. What is a Parent Chain? 🌿 An organic molecule's parent chain is the longest chain of atoms (mostly carbon atoms) that contains the molecule's highest-priority functional group. What is a Functional Group? 🔬 A functional group is a part of a molecule that can participate in chemical reactions. Common Functional Groups and Their Names Functional Group Formula Examples Carboxylic acid RCOOH Ethanoic acid, propanoic acid, butanoic acid Ester RCOOR' Ethyl ethanoate, methyl propanoate Acid chloride RCOCl Ethanoyl chloride, propanoyl chloride Amide R'C(O)NR2 N,N-dimethyl propanamide, N-ethylbutanamide Nitrile RCN Ethanenitrile, propanenitrile Aldehyde RCHO Ethanal, propanal, butanal Ketone RCOR' 2-butanone, 3-butanone, 2-pentanone Alcohol ROH Methanol, ethanol, propanol Phenol PhOH Amine R'NR2 N,N-dimethylpropanamine, N-ethylcyclohexanamine Alkene RCH=CHR' Ethene, propene, butene Alkyne RC≡CR' Ethyne, propyne, butyne Ether ROR' Methoxyethane, ethoxypropane Alkyl halide RX Fluoro, chloro, bromo, iodo IUPAC Names for Simple Hydrocarbon Parent Chains Parent Molecular Formula Number of Carbons Condensed Structure Alkane Name CnH2n+2 2 CH4 Methane CnH2n+2 3 C2H6 Ethane CnH2n+2 4 C3H8 Propane CnH2n+2 5 C4H10 Butane CnH2n+2 6 C5H12 Pentane CnH2n+2 7 C6H14 Hexane CnH2n+2 8 C7H16 Heptane https://www.turbolearn.ai/content/b1a64f3a-2502-44cd-ad1e-e4753997601b 1/5 9/9/24, 11:48 AM IUPAC Naming System for Organic Compounds Parent Molecular Formula Number of Carbons Condensed Structure Alkane Name CnH2n+2 9 C8H18 Octane CnH2n+2 10 C9H20 Nonane CnH2n+2 11 C10H22 Decane Simple Substituent Names and Structures Isopropyl: (CH3)2CH- Isobutyl: (CH3)2CHCH2- tert-Butyl: (CH3)3C- sec-Butyl: CH3CH(CH3)CH2- Naming Alkanes 1. Find the parent chain: the longest carbon chain. 2. Count the number of carbon atoms in the parent chain and match that number to the name from the chart. 3. Identify and number the substituents (appendages dangling off the parent chain) in whichever direction gives them the lowest number. 4. Write the name as a single word: Substituents (replace ane with yl) + parent chain. Naming Cycloalkanes Put the prefix cyclo before the alkane to indicate it's a ringed compound. Use the prefix cis to indicate that two substituents are pointing in the same direction. Use the prefix trans to indicate that two substituents are pointing in opposite directions. For cycloalkanes with more than two substituents, use the R/S system. Naming Alkyl Halides Follow the rules for naming alkanes, except: Use the prefixes fluoro, chloro, bromo, or iodo, with numbers, to identify each halogen substituent and its position. Alternatively, use the suffixes yl fluoride, yl chloride, yl bromide, or yl iodide at the end of the parent name for simple alkyl halides. Naming Alkenes Follow the rules for naming alkanes, except: Use ene instead of ane at the end of the molecule's name. Add a number at the beginning of, or within, the name to indicate where the C=C bond starts. Add the prefixes cis or trans, or alternatively, E or Z, at the beginning of the name to indicate the C=C bond's stereochemistry. Cis and Trans Alkenes Don't confuse cis/trans alkenes with cis/trans cyclics. For alkenes, if you have two substituents on opposite sides of the C=C bond, and they are pointing in opposing directions, then they are trans to each other. If they point in the same direction, then they are cis. E/Z Naming of Alkenes https://www.turbolearn.ai/content/b1a64f3a-2502-44cd-ad1e-e4753997601b 2/5 9/9/24, 11:48 AM IUPAC Naming System for Organic Compounds If the two highest-priority groups are on the same side, then it is a Z alkene. If the two highest-priority groups are on opposite sides, then it is an E alkene. How to Determine Priority 1. Highest atomic number = highest priority. 2. If there's a tie, then keep going out one atom at a time until you break the tie. 3. Multiple-bonded atoms are counted as the same number of single-bonded atoms. Naming Alkynes Follow the rules for naming alkanes, except: Use yne instead of ane at the end of the molecule's name. Add a number at the beginning of, or within, the name to indicate where the C≡C bond starts.## Functional Groups 🧬 Carboxylic Acid and Derivatives Functional Group General Formula Examples Carboxylic Acid RCOOH Ethanoic acid, Propanoic acid, Butanoic acid Ester RCOOR' Ethyl ethanoate, Methyl propanoate Acid Chloride RCOCl Ethanoyl chloride, Propanoyl chloride Amide RCONR'R'' N,N-dimethyl propanamide, N-ethylbutanamide Aldehydes and Ketones Functional Group General Formula Examples Aldehyde RCHO Ethanal, Propanal, Butanal Ketone RCOR' 2-Butanone, 3-Butanone, 2-Pentanone Alcohols, Ethers, and Amines Functional Group General Formula Examples Alcohol ROH Methanol, Ethanol, Propanol Ether ROR' Methoxyethane, Ethoxypropane Amine RNH2, R2NH, R3N Methylamine, Dimethylamine, Trimethylamine Naming Alcohols 📚 When naming alcohols, we follow the rules for naming alkanes, except: Our parent chain is the longest carbon chain that has the OH (hydroxyl) group on it, even if there are longer carbon chains that don't have the OH on them. Number the carbon chain in the direction that gives the smallest number to the carbon bonded to the hydroxyl (OH) group. Naming Ethers 📚 https://www.turbolearn.ai/content/b1a64f3a-2502-44cd-ad1e-e4753997601b 3/5 9/9/24, 11:48 AM IUPAC Naming System for Organic Compounds When naming ethers, we follow these steps: 1. Name the two alkyl groups as substituents with the word ether at the end. 2. Consider the longest carbon chain to be the parent chain and the alkoxy group to be a substituent. Naming Amines 📚 Amines can be 1° (primary), 2° (secondary), or 3° (tertiary), depending on how many carbons are bonded to the nitrogen. Primary amines, RNH2, are named by adding the suffix -amine to the name of the organic substituent. Symmetrical and secondary amines are named by adding di- or tri- to the alkyl group. Asymmetrical amines are named as N-substituted primary amines, with the largest alkyl group being named as a parent chain. Naming Aldehydes and Ketones 📚 When naming aldehydes and ketones, we follow these steps: For aldehydes, the parent chain is the longest carbon chain that contains the aldehyde. For ketones, there are two ways to name them: 1. Name each chain on either side of the C=O (carbonyl) and then follow it with the word ketone. 2. Name the entire parent chain as you would with an alkane, but replace the e in the alkane name with a number to indicate the position of the C=O (carbonyl) bond, followed by the suffix -one. Naming Carboxylic Acid Derivatives 📚 When naming carboxylic acid derivatives, we follow these steps: For carboxylic acids, the parent chain is the longest carbon chain that contains the carboxylic acid. For acid halides, the parent chain is the longest carbon chain that contains the acid halide. For esters, the alkyl group attached to the ester oxygen gets listed first, as a substituent, with the suffix -yl. For amides, any alkyl groups attached to the nitrogen get listed as N-methyl, N-ethyl, N-propyl, etc. Naming Substituted Benzenes 📚 When naming substituted benzenes: Identify the parent chain, which is the benzene containing the highest-priority functional group. The carbon atom in the ring that is attached to the priority functional group is numbered as carbon #1. Number around the ring in whichever direction (clockwise or counterclockwise) gives the lowest number at the first point of difference. Spiro Alkanes 🌀 Spiro alkanes are carbon/hydrogen molecules that have two or more rings fused together at single carbon points. Naming Spiro Alkanes 📚 IUPAC names for spiro alkanes have the format spiro[a.b]parent name. Count the total number of carbons across the entire molecule. https://www.turbolearn.ai/content/b1a64f3a-2502-44cd-ad1e-e4753997601b 4/5 9/9/24, 11:48 AM IUPAC Naming System for Organic Compounds Count the number of carbons to the left, and to the right of your spiro-carbon center. Write your final IUPAC name as spiro[a.b]parent name. Bicyclic Alkanes 🌀 Bicyclic alkanes are carbon/hydrogen molecules that have two or more rings fused together across multi-carbon bridges. Naming Bicyclic Alkanes 📚 IUPAC names for bicyclic alkanes have the format bicyclo[a.b.c]parent name. Count the total number of carbons across the entire molecule. Count the number of carbons in each bridge. Write your final IUPAC name as bicyclo[a.b.c]parent name. https://www.turbolearn.ai/content/b1a64f3a-2502-44cd-ad1e-e4753997601b 5/5