ORGANIC CHEMISTRY 3540

SKELETAL STRUCTURES

FUNCTIONAL GROUPS

ISOMERS

SKELETAL STRUCTURES

VITAMIN A

NEED AN EASIER WAY TO SEE STRUCTURE!

SKELETAL STRUCTURE OF HEXANE

RULES FOR DRAWING SKELETAL STRUCTURES

1. CARBON ATOMS USUALLY AREN'T SHOWN.

CARBON IS ASSUMED TO BE AT THE INTERSECTION OF TWO LINES OR AT THE END OF A LINE.

2. HYDROGEN BONDED TO CARBON IS NOT SHOWN.

CARBON HAS A VALENCE OF 4 SO WE CAN MENTALLY SUPPLY THE CORRECT NUMBEROF HYDROGENS.

3. ATOMS OTHER THAN CARBON AND HYDROGEN ARE SHOWN (AS WELL AS HYDROGEN BONDED TO NON-CARBON ATOMS).

4. PI BONDS ARE SHOWN WITH A DOUBLE OR TRIPLE LINE.

SKELETAL STRUCTURE OF VITAMIN A

FUNCTIONAL GROUPS

• 11+ MILLION ORGANIC COMPOUNDS!

• HOW CAN WE UNDERSTAND THEIR CHEMISTRY?
  • THE CHEMISTRY OF EVERY ORGANIC MOLECULE, REGARDLESS OF SIZE AND COMPLEXITY, IS DETERMINED BY THE FUNCTIONAL GROUPS IT CONTAINS!

• TWO ISOMERS, DIFFERENT FUNCTIONAL GROUP
• SAME FUNCTIONAL GROUP

• WHICH FUNCTIONAL GROUPS DO WE HAVE TO KNOW?
  • C and H only

  • C, H and O

  • C, H, and (N, O, and/or X)

IF THERE ARE ONLY A LIMITED NUMBER OF FUNCTIONAL GROUPS:

• WHY ARE THERE SO MANY COMPOUNDS?
  • ISOMERS!!!!
    • STRONG C-C, C-H, C-O, etc., BONDS DUE TO HYBRIDIZATION

    • CARBON FORMS FOUR BONDS

  • C₄H₁₀ 2 ISOMERS

  • C₅H₁₂ 3 ISOMERS

  • C₆H₁₄ 5 ISOMERS

  • C₇H₁₆ 9 ISOMERS

  • C₈H₁₈ 18 ISOMERS

  • C₉H₂₀ 35 ISOMERS

  • C₁₀H₂₂ 75 ISOMERS

  • C₁₅H₃₂ 4,347 ISOMERS

  • C₂₀H₄₂ 366,319 ISOMERS

  • C₃₀H₆₂ 4,111,846,763 ISOMERS