Organic Chemistry: Nomenclature Quiz

IUPAC Nomenclature Rules

• Substituents must be numbered for proper identification along the parent chain.
• Rank substituents alphabetically when tied at chain locations, comparing the first substituent found in both numbering directions.
• Common carbon substituents end with "-yl" (e.g., methyl, ethyl).
• For identical substituents, use prefixes (di-, tri-, tetra-) and indicate chain locators with a hyphen.
• The final compound name combines substituents and the parent chain with no spaces.

Naming Complex Substituents

• Identify the longest carbon chain of the complex substituent starting with the carbon attached to the parent as #1.
• Number carbons in the longest chain sequentially from #1.
• List substituents alphabetically, using chain locators before each and applying the same rules for identical substituents.
• The name concludes with "-yl" suffix representing the longest chain, enclosed in parentheses.

Common Complex Substituents

• Isopropyl (1-methylethyl)
• Isobutyl (2-methylpropyl)
• Sec-butyl (1-methylpropyl)
• Tert-butyl (t-butyl, 1,1-dimethylethyl)

Naming Bicyclic Compounds

• List substituents before the parent chain.
• Use "bicyclo-" prefix for the parent chain, followed by the count of carbons between bridgehead carbons.
• End with the alkane name reflecting total carbons in the ring system.
• Number starting from one bridgehead, prioritizing the longest path.

Naming Spiro Bicyclic Compounds

• Precede the parent name with "spiro-" and list the number of carbons in each ring, excluding the spiro carbon.
• Complete the name with the alkane name for all carbons, including the spiro carbon.
• Number starting from the smaller ring adjacent to the spiro-carbon for lower chain locator.

Nomenclature of Common Functional Groups

• Carboxylic Acid: "-oic acid" (e.g., ethanoic acid)
• Ester: "-oate" (e.g., ethyl propanoate)
• Amide: "-amide" (e.g., ethanamide)
• Nitrile: "-nitrile" (e.g., propanenitrile)
• Aldehyde: "-al" (e.g., propanal)
• Ketone: "-one" (e.g., propan-2-one)
• Alcohol: "-ol" (e.g., propan-2-ol)
• Amine: "-amine" (e.g., propan-2-amine)

Stereochemistry Vocabulary

• Chiral compounds have non-superimposable mirror images termed enantiomers, indicating optical activity.

Nomenclature Rules

• For multiple identical substituents, use locators separated by commas and prefixes such as di-, tri-, or tetra-.
• List substituents in alphabetical order using the first letter of the complex substituent's name.
• Name ends with the longest chain using a -yl suffix, no space between substituents and chain name.
• Complex substituents should be named using the appropriate locator and enclosed in parentheses for the parent chain.

Common Complex Substituents

• Isopropyl (1-methylethyl)
• Isobutyl (2-methylpropyl)
• Sec-butyl (1-methylpropyl)
• Tert-butyl (1,1-dimethylethyl)

Naming Bicyclic Compounds

• Substituents named similarly to alkanes, starting with the bicyclo- prefix.
• List the number of carbons between bridgehead carbons in each path, in brackets from highest to lowest.
• Parent chain named with alkane name that includes all carbons in the ring system.

Acid/Base Extractions

• Amines extracted with HCl.
• Carboxylic acids removed using NaHCO3 or NaOH.
• Phenols extracted with NaOH.

Distillation Techniques

• Simple Distillation: Best for liquids with a large boiling point difference (>100ºC) and when one major component exists.
• Fractional Distillation: Equivalent to conducting multiple simple distillations.

Chromatography Methods

• Gas Chromatography (GC): Separation based on boiling points; lower boiling compounds elute first.
• Thin Layer Chromatography (TLC): Separation via polarity; more polar compounds have lower Rf values.
• Column Chromatography: Similar to TLC; polarity-based retention time.

Recrystallization

• Utilizes differences in solubility; higher solubility at high temperatures results in purifications.

Infrared (IR) Spectroscopy

• Detects vibrational transitions in chemical bonds to identify functional groups.
• Common absorption peaks for various bonds:
  • Aromatic C-C: 1500-1600 cm⁻¹
  • C=O: ~1710 cm⁻¹ (can shift for esters)
  • O-H (alcohol): ~3400 cm⁻¹ (broad peak)

Mass Spectrometry

• Involves electron ejection leading to molecule fragmentation.

Reaction Mechanisms

• E1: Occurs with a tertiary electrophile, requires a strong base, favors polar aprotic solvents.
• E2: Reactions favor anti-periplanar arrangement, possible with strong bases.

Free Radical Halogenation

• Utilizes Cl₂ or Br₂ for the selective addition of halogens to alkenes; mechanisms include initiation, propagation, and termination.

Diels-Alder Reaction

• A 4+2 cycloaddition involving a diene and a dienophile, characterized by a concerted mechanism and syn addition.

Criteria for Aromatic Compounds

• Must be cyclic, conjugated, planar, and contain 4N+2 π electrons.
• Antiaromatic compounds have 4N π electrons and exhibit instability.

Electrophilic Aromatic Substitution (EAS)

• Key reactions include nitration, sulfonation, and Friedel-Crafts reactions, with specific electrophiles for each.

Alcohols and Ethers

• Alcohols are named with an -ol suffix, ethers as alkoxy or alkyl alkyl ethers.
• Phenols have distinct acidity compared to other alcohols; acidity trend: methyl > 1º > 2º > 3º.

Carbonyl Compounds

• Aldehydes end in -al, and ketones end in -one.
• Carbonyls react with alcohols to form hemiacetals/acetal, 1º amines to form imines, and undergo nucleophilic addition reactions.

Carboxylic Acids and Derivatives

• Nomenclature features the -oic acid suffix for primary functionalities.
• Reactivity order in nucleophilic acyl substitution: acid chlorides > anhydrides > esters/carboxylic acids > amides.

Alpha Substitution Reactions

• Involve enolates formed from carbonyl compounds through keto/enol tautomerism.
• Aldol reactions occur via enolate or enol addition, and Claisen condensation involves enolate addition to esters.