p2

• Stereochemical drawings


  • Flying wedge
  • Fischer
  • Newman
  • Sawhorse projection
• Stereochemistry


  An important aspect of Organic Chemistry where you must be able to draw structures which clearly indicate the stereochemical orientation of the various groups on a molecule
• Wedge


  • A symbol used to indicate the position of a bond or group relative to the plane of the paper or screen
  • A solid wedge indicates this bond or group is projecting out towards the viewer
  • A broken (hashed) wedge indicates this bond or group is receding away from the viewer
• The carbon-hydrogen bond on the solid red wedge is pointing out of your computer screen towards you
• The carbon-carbon bond on the blue broken wedge is receding away from you
• The bonds represented by lines (i.e., not shown in wedges) lie in the plane of your computer screen
• Fischer projection


  A simpler method of drawing molecules introduced by the German chemist Emil Fischer in 1891, based on the projection of the tetrahedral chirality centers onto a plane
• The Fischer projection is particularly used for carbohydrates and amino acids
• Sawhorse projection


  A representation of molecular structure, from an oblique angle, somewhat similar to Newman and zig-zag (Natta) projections, named after its similar appearance to a carpenter's sawhorse
• Molecular structure representations


  • Sawhorse projection
  • Zig-zag (Natta) projection
  • Newman projection
• Newman projection


  Drawings used to help visualize the 3-dimensional structure of an organic molecule, representing a side view of C-C alkane, or a single bond, as well as its side groups in each direction
• Molecular structures


  • Methane
  • Ethane