Lecture Notes: Organic Chemistry

Introduction to Organic Chemistry

• Definition: Subdiscipline of chemistry focusing on the study of organic compounds and materials containing carbon atoms.
• Structure Study: Determines structural formula of compounds.
• Properties Study: Includes physical and chemical properties, chemical reactivity.
• Reactions Study: Involves chemical synthesis of natural products, drugs, and polymers.

Representations of Organic Compounds

• 5-Dihydroprogesterone Representations:
  • Line-angle representation: Carbon atoms implied at line termini/vertices, hydrogens implied by valence.
  • Ball-and-stick representation.
  • Space-filling representation.

Range of Chemicals in Organic Chemistry

• Hydrocarbons: Compounds of carbon and hydrogen.
• Organometallic Chemistry: Study of compounds containing carbon-metal bonds.
• Importance: Organic compounds are crucial for life, involved in pharmaceuticals, petrochemicals, agrichemicals, etc.

History and Development

• Vitalism: Pre-18th-century belief in a 'vital force' in organic compounds.
• Friedrich Wöhler (1828): Synthesized urea from inorganic compounds, disproving vitalism.
• Significant Contributors: Justus von Liebig, William Henry Perkin (discovered Perkin's mauve dye).

Chemical Structure and Synthesis

• Concept of Structure: Developed by Kekulé and Couper, suggesting tetravalent carbon atoms form lattices.
• Pharmaceutical Industry: Began with Bayer's manufacturing of aspirin.
• Paul Ehrlich: Initiated chemotherapy, developed Salvarsan for syphilis.

Techniques and Methods

• Spectroscopy and Analysis:
  • NMR Spectroscopy: Used for structure and stereochemistry.
  • Mass Spectrometry: Determines molecular weight and structure.
  • Crystallography: Determines molecular geometry.
• Separation Techniques: Chromatography, distillation, crystallization.

Properties of Organic Compounds

• Physical Properties:
  • Melting and boiling points indicate purity and identity.
  • Typically hydrophobic but can vary with functional groups.
• Solid State Properties: Include piezoelectricity and electrical conductivity in polymers.

Nomenclature: Naming Organic Compounds

• Systematic Nomenclature: Follows IUPAC rules, based on parent structures and modifications.
• Nonsystematic Nomenclature: Simpler, used for complex molecules.
• SMILES and InChI: Computer-readable formats for chemical structures.

Classification of Organic Compounds

• Functional Groups: Central to classifying structures and predicting properties.
• Aliphatic Hydrocarbons: Include alkanes, alkenes, and alkynes.
• Aromatic Compounds: Include conjugated systems like benzene.
• Heterocyclic Compounds: Contain heteroatoms in rings, prevalent in various biochemical compounds.

Polymers and Biomolecular Chemistry

• Polymerization: Formation of polymers from monomers.
• Synthetic vs. Natural Polymers: Synthetic are manufactured, natural occur without human intervention.
• Biochemical Polymers: Include DNA, RNA, peptides, polysaccharides.

Reactions in Organic Chemistry

• Types of Reactions: Addition, elimination, substitution, pericyclic, rearrangement, and redox reactions.
• Synthetic Organic Chemistry: Involves designing syntheses for complex compounds.
• Retrosynthesis: Strategy of designing a synthesis by breaking down a target molecule into simpler precursors.

These notes summarize key concepts in organic chemistry, capturing its historical development, techniques, properties, and significance in various applications.