CHEM2100 CH 9 Part 2 FS2024

9.9 An Introduction to Organic Synthesis

• Conceptual Understanding

  • Organic synthesis can be likened to planning a road trip.

  • Just as you need a roadmap for your journey, a systematic pathway is required for a successful organic synthesis.

• Worked Example 9.1

  • Demonstrates the need for a clear synthesis route.

  • Example starts with a given target molecule to synthesize.

Transitioning from Student to Chemist

• From Learning to Application

  • It is crucial to transition your mindset from a student of organic chemistry to an active organic chemist.

  • This transition means actively engaging in the process of organic synthesis.

• Retrosynthetic Analysis

  • Work backward from the final product to determine the synthesis route.

  • Key questions include: "What was the immediate precursor of that product?"

  • Keep in mind the starting material but do not let it dominate your planning focus.

  • There is no hidden secret to effectively planning organic syntheses.

Worked Examples for Organic Synthesis

• Worked Example 9.1

  • Example:

    • Reacting 1-pentyne with an alkyl halide (RX) to form cis-2-Hexene.

    • Reactants: CH3CH2C=CCH3 + RX.

• Worked Example 9.2

  • Example of combining acetylenes with alkyl halides.

    • Ethene + RX to produce 2-Bromopentane.

    • Reaction: Br HC=CH + RX CH3CH2CH2CHCH3.

• Worked Example 9.3

  • Involves synthesis challenges using acetylene and alkyl halides.

    • Example problems include synthesizing:

      • a) Decane

      • b) 2,2-dimethylhexane

      • c) Hexanal

      • d) 2-heptanone

Synthesis of Specific Molecules

• Synthesis of Decane

  • Review techniques and reagents needed.

• Synthesis of 2,2-Dimethylhexane

  • Detailed steps and methodologies for completion.

• Synthesis of Hexanal

  • Key synthetic routes for producing this molecule.

• Synthesis of 2-Heptanone

  • Methods and suitable reagents discussed.