Chapter 14: Organic Compounds with Oxygen and Sulfur

Chapter 14 Organic Compounds with Oxygen and Sulfur

Overview of Organic Compounds

Categories of Compounds

  • Alcohols

  • Phenols

  • Thiols

  • Ethers

Alcohols

Definition

  • An alcohol contains a hydroxyl group (–OH) that replaces a hydrogen atom in a hydrocarbon.

  • A phenol contains a hydroxyl group (–OH) attached to a benzene ring.

Naming Alcohols

IUPAC System

  • Replace -e with -ol in the name of the corresponding alkane.

Common Names

  • Use the name of the alkyl group followed by "alcohol".

Formula Examples

  • Methanol:

    • IUPAC: CH3─OH

    • Common Name: Methyl alcohol

  • Ethanol:

    • IUPAC: CH3─CH2─OH

    • Common Name: Ethyl alcohol

  • Propanol:

    • IUPAC: 1-propanol

    • Common Name: Propyl alcohol

  • Isopropanol:

    • Common Name: Isopropyl alcohol

Guide to Naming Alcohols

  1. Identify the longest carbon chain containing the –OH group.

  2. Name aromatic alcohols as phenols.

  3. Number the chain, starting from the end closer to the –OH group.

  4. State the location and name of each substituent relative to the –OH group.

Naming Examples

  • 1. CH3─CH2─CH2─OH

    • Propanol

  • 2. CH3─CH─CH─CH2─CH3

    • Pentanol

  • 3. Cyclopentanol

Additional Naming Practice

  • Example 1: CH3─CH2─CH2─CH2─OH

    • Longest chain: Butanol, Numbering: 1-Butanol

  • Example 2: CH3─CH─CH─CH2─CH3

    • Longest chain: Pentanol, Numbering: 2-Pentanol

Structure and Properties of Alcohols

  • General formula: ROH

  • Contains a bent shape O atom similar to H2O with a bond angle akin to tetrahedral geometry.

  • Capable of intermolecular hydrogen bonding due to H atom bonded to O atom.

  • Exhibits higher boiling and melting points compared to hydrocarbons of similar weight and structure due to stronger intermolecular forces.

Solubility

  • Alcohols are generally soluble in organic solvents.

  • Low molecular weight alcohols (6 Cs or less) are soluble in water, while those with 6 or more Cs are not.

Typical Alcohols

  • 2-Propanol (Isopropyl alcohol):

    • Commonly known as rubbing alcohol.

  • Ethylene Glycol (1,2-Ethanediol):

    • Used as antifreeze.

  • Glycerol (1,2,3-Propanetriol):

    • Used in various applications including pharmaceuticals.

Methanol Poisoning

  • Methanol, also known as methyl alcohol, is highly toxic.

  • Found in products like windshield washer fluid and paint strippers.

  • Rapidly absorbed and oxidized in the body to formaldehyde and then to formic acid, which lowers blood pH.

  • As little as 30 mL of methanol can lead to coma or death.

Ethanol

  • Ethanol (CH3CH2OH) acts as a depressant and is responsible for more deaths than any other drug.

  • Metabolized at different rates: 12–15 mg/dL/hour for social drinkers; 30 mg/dL/hour for alcoholics.

Alcohol in the Body

  • After ingestion, alcohol is converted by liver enzymes into toxic acetaldehyde, which impairs coordination.

Effect of Alcohol on Behavior

Blood Alcohol Levels (Table 12.2)

  • 0.025: Slightly dizzy, talkative.

  • 0.050: Euphoria, loud talking.

  • 0.10: Loss of inhibition, loss of coordination.

  • 0.20: Intoxication, quick to anger.

  • 0.30: Unconscious.

  • 0.40-0.50: Coma and death.

Phenols in Medicine

Definition

  • Phenol is the IUPAC name for benzene with a hydroxyl group.

  • Used in antiseptics and disinfectants.

Examples

  • Resorcinol

  • 4-Hexylresorcinol

  • Propofol: Used for induction and maintenance of general anesthesia (administered via IV).

Derivatives of Phenol

  • Active ingredients in essential oils of cloves, vanilla, nutmeg, and mint.

BPA – Bisphenol A

Applications

  • Found in polycarbonate plastics and resins.

  • Used to coat metal products such as cans.

  • Found in containers and baby bottles.

Concerns

  • Majority detected in urine from a national health survey (93% of samples).

  • Recommended to avoid microwaving polycarbonate plastic containers.

  • Use BPA-free baby bottles.

Hand Sanitizers

  • Many contain ethanol.

  • Previously contained Triclosan, which was banned by the FDA due to health concerns related to antibiotic resistance and hormonal effects.

Thiols

Definition

  • Thiols contain sulfur and resemble alcohols, featuring a thiol (–SH) group.

  • Known for their strong, unpleasant odors and found in various foods.

  • Cannot form hydrogen bonds, thus have lower melting and boiling points than comparable alcohols.

Ethers

Definition

  • Ethers contain an –O– between two carbon groups.

  • Common name derived from the alkyl groups attached to the ether.

Anesthetic Uses

  • Historically, diethyl ether was used for surgery but had drawbacks like nausea and flammability.

  • More modern anesthetics are non-flammable.

Properties of Ethers

  • Higher melting and boiling points than hydrocarbons of similar molecular weight but lower than alcohols of the same weight.

Aldehydes and Ketones

Carbonyl Groups

  • The carbonyl group consists of a polar carbon-oxygen double bond, with oxygen being highly electronegative.

  • Contains lone pairs on the oxygen atom, imparting polarity.

Aldehydes

  • Naming: Change -e to -al in the alkane name.

  • Examples:

    • Methanal (Formaldehyde)

    • Ethanal (Acetaldehyde)

Common Uses

  • Aldehydes serve as flavorings in food and fragrances (e.g., benzaldehyde, vanillin).

Ketones

  • Naming: Replace -e with -one.

  • Examples:

    • Acetone (solvent nail polish remover)

    • Butanedione (butter flavoring in margarine).

Diabetes and Ketones

  • Insufficient glucose leads the liver to synthesize glucose from non-carbohydrates, breaking down fats to produce Acetyl CoA which leads to keto production.