IUPAC Nomenclature of Ethers and Their Properties

Ethers

• IUPAC nomenclature rules:
  • Write names of two substituents alkyl linked to the O atom
  • Write suffix (ether)
  • Example: CH3‒O‒CH2CH3: ethyl methyl ether
• No hydrogen bonding is possible in R—O—R
• Boiling points are much lower than alcohols, similar to haloalkanes
• Water solubility is much less than alcohols
• MeOMe and EtOEt have some water solubility, but larger ethers are insoluble, similar to alkanes
• Fairly unreactive, nonpolar solvents for organic reactions

Aldehydes

• Organic compounds containing a carbonyl group (C=O) and at least one hydrogen atom bonded to the carbon in the carbonyl group
• General formula: RCHO, where R is a hydrocarbon (aliphatic or aromatic) group
• Electropositive carbonyl carbon pulls electrons away from O—H bond
• Resulting carboxylate anion is stabilized by resonance
• Electron withdrawing substituents increase acidity
• Carboxylate anion is named as an alkanoate (e.g., formate, acetate, pentanoate)

Synthesis of Carboxylic Acids

• Oxidation of primary alcohols and aldehydes by Cr(VI) reagents
• Reaction of carboxylic acid: ester formation

Esters

• Organic compounds derived from carboxylic acid and alcohol
• General formula: RCOOR*, where R is a hydrogen or hydrocarbon (aliphatic or aromatic) group, and R* is a hydrocarbon group
• IUPAC nomenclature rules:
  • Write suitable prefix for #C, then suffix (….yl) for the side derived from alcohol
  • Write suitable prefix for #C, then suffix (….anoate) for the side derived from carboxylic acid
  • Example: Methyl methanoate, Ethyl butanoate

Amines

• Organic compounds containing the C–N linkage
• General formula: RNH2, R2NH, or R3N, where R is a hydrocarbon group, R* and R** are a hydrogen or hydrocarbon (aliphatic or aromatic) group
• IUPAC nomenclature rules:
  • Write names of all substituents alkyl linked to the N atom
  • Write suffix (amine)
  • Example: Ethyl amine, Dimethyl amine, Methyl propyl amine, Trimethyl amine
• Physical properties:
  • N—H less polar than O—H
  • Amines have lower boiling points than alcohols due to weaker hydrogen bonds
  • Tertiary amines have lower boiling points than primary and secondary amines
  • Small amines are soluble in water, branching increases solubility
  • Most amines smell like rotting fish

Ketones

• Boiling points are higher than alkanes due to polarity
• Small carbonyl compounds (< 7 C) are water soluble due to polarity (e.g., acetone)

Oxidation of Alcohols

• Secondary ROH gives ketones
• Primary ROH gives aldehydes

Ozonolysis of Alkenes

• Yields ketones or aldehydes

Hydration of Alkynes

• Markovnikov hydration yields ketones
• Anti-Markovnikov hydration yields aldehydes

Carboxylic Acids

• Organic compounds containing the carboxyl group (–COOH)
• General formula: RCOOH, where R is a hydrogen or hydrocarbon (aliphatic or aromatic) group
• IUPAC nomenclature rules:
  • Determine longest continuous chain of carbon atoms starting from carboxyl group (–COOH) (parent name)
  • Put number for C atoms in the continuous chain of carbon starting from carboxyl group (–COOH)
  • Put numbers and names of substituents alkyl
  • Write suitable prefix for #C, then suffix (….anoic acid)
  • Example: Methanoic acid, Ethanoic acid (formic acid, acetic acid)
• Planar sp2 hybridized structure
• Hydrogen bonded dimers
• Acid-base characteristics

Aromatic Compounds

• Functional group: a group of atoms responsible for the chemical behavior of the parent molecule
• Reactions of benzene: halogen substitution, nitro substitution

Alkyl Halides

• Organic compounds containing at least one carbon‒halogen (Cl, Br, I) bond
• General formula: R–X, where R is a hydrocarbon (aliphatic or aromatic) group, X is Cl, Br, or I
• IUPAC nomenclature rules:
  • Determine longest continuous chain of carbon atoms in that pass with carbon which links up with halogen (parent name)
  • Put number for C atoms in the continuous chain of carbon starting from terminal C which near to carbon‒halogen bond C‒X
  • Put numbers and names of substituents alkyl
  • Put number carbon which links up with halogen
  • Put numbers and names of halogen as halo (chloro, bromo, iodo), if two halogen or more halogen use (di-, tri-, or tetra- ,…)
  • Write suitable prefix for #C, then suffix (….ane)
  • Example: Flouroethane, 1-iodopropane, 2-bromobutane, 2-bromo-3-methylpentane, 2,3-dichloropentane, 2,4-dibromopentane
• For two halogen substituents on benzene ring:
  • Use prefixes o- (ortho-), m- (meta-), or p- (para-)