Ethers

Page 1: Introduction to Ethers

Ethers

  • Definition: An ether consists of an oxygen atom attached by single bonds to two carbon groups, which can be alkyl or aromatic groups.

  • Example: Forane (isoflurane) is an inhaled anesthetic.

Page 2: Structure of Ethers

Structure Details

  • Ethers contain an oxygen atom that links two carbon groups (either alkyl or aromatic rings).

  • Naming Convention: Common names usually consist of the alkyl names of the attached groups, followed by the term "ether."

Page 3: Naming Ethers

Naming Systems

  • Common Names: Most ethers are named using common nomenclature; the names of alkyl or aromatic groups are listed in alphabetical order.

  • IUPAC Naming: Involves using an alkoxy group (smaller alkyl group + oxygen) followed by the longer carbon chain name. Common names will be primarily used in this text.

Page 4: Learning Check on IUPAC Naming

IUPAC Name Inquiry

  • Assign the IUPAC name for the provided ether structures.

Page 5: Problem Analysis for IUPAC Naming

Analyzing IUPAC Naming Steps

  • Given: Structure of the ether.

  • Need: Determine the IUPAC name.

  • Connect: Use the alkoxy group and carbon chain details for naming.

Step-by-step Approach

  1. Write the alkane name of the longer carbon chain.

Page 6: Continued Problem Analysis for IUPAC Naming

Naming Steps Continued

  1. Continue from step 1 to write the longer carbon chain's name.

  2. Number the carbon chain from the end nearest the alkoxy group to determine the correct location.

Page 7: Ethers in Anesthesia

Chemistry Link to Health

  • Definition: Anesthesia involves the loss of sensation and consciousness.

  • General Anesthetic Functions: Block signals to brain awareness centers, resulting in loss of memory, pain feeling, and induced artificial sleep.

  • Example: Forane (isoflurane) is an inhaled anesthetic used in modern procedures.

Page 8: Historical Overview of Ethers in Anesthetics

Ethers in Historical Context

  • Ethers were used in anesthetics for hundreds of years until the 1950s.

  • Progression: New anesthetics emerging that still incorporate the ether group but replace hydrogen atoms with halogens to lower volatility and flammability.

Page 9: Ether Synthesis Process

Production of Ethers

  • Reaction Overview: Reaction of ethanol with sulfuric acid leading to ether.

  • Equation Representation: H—C—C▬Ö±H + H▬Ö—C—C—H
    H₂SO₄ -> H-C-C-O-C-C-H + HOH

Page 10: Properties of Ethers

Characteristics of Ethers

  • Volatility: Ethers are extremely volatile compounds.

  • Polarity: Ethers are much less polar than compounds containing hydroxyl groups.

  • Intermolecular Forces: Cannot form hydrogen bonds, leading to weak intermolecular forces (IMFs).

Page 11: Introduction to Thiols

What are Thiols?

  • Definition: Thiols contain a -SH (thiol) group.

  • Common Odors: Often have strong and sometimes unpleasant odors, and are found in foods like cheese, onions, garlic, and oysters.

  • Practical Use: Thiols are used to detect gas leaks due to their distinctive smell.

Page 12: Naming Thiols

Thiol Nomenclature

  • Also known as Mercaptans: Thiols are a class of sulfur-containing organic compounds.

  • IUPAC Naming Convention: Named by adding "thiol" to the alkane name of the longest carbon chain and numbering from the end near the thiol group.

Page 13: Characteristics of Specific Thiols

Notable Thiols

  • Methanethiol: Characteristic odor reminiscent of oysters, cheddar cheese, onions, and garlic.

  • Other examples include:

    • 2-propene-1-thiol found in garlic.

    • 1-propanethiol responsible for onion odor, which is a lacrimator (tear-inducing).

Page 14: Oxidation of Thiols

Oxidative Reactions in Thiols

  • Oxidation Process: Involves loss of an H atom from each of the two -SH groups.

  • Product Formation: Results in the formation of disulfides.

  • Relevance: Disulfide bonds are significant in proteins, notably in hair, where they cross-link amino acids like cysteine.