Quick review of `stereochemical’ ideas so far: Chiral

(crossed Nicols) polarimeter Quicky review (continued) condition for molecules to exhibit `handedness’ ? Tetrahedral central atom must be connected to 4 non-equivalent chemical groups Special word used to describe to above condition? Chiral handedness is experimentally detected with what device ? (crossed Nicols) polarimeter

Name of quantity measured with a polarimeter: Quicky review (continued) Name of quantity measured with a polarimeter: Optical rotation,  (in degrees) If you turn the analyzing polarizer counterclockwise to find , the sign of the polarization is….. Negative (-) Does a right-handed sugar always produce a (+) rotation ? No…no connection between sign and right /left-handedness What does the `D’ stand for in the specific rotation value DT ? Wavelength of light used is the orange-colored sodium D line at 589 nm

Coming out of the slide towards you Quicky review (continued) Name for the 2D `crossed’ representation of a chiral center like that shown here: Fischer projection Which way are the horizontal species above oriented relative to the plane of this slide ? Coming out of the slide towards you Which way are the vertical species above oriented relative to the plane of this slide ? Moving into the slide away from you

Fischer’s D and L notation Quicky review (continued) Name the icky, hard way that Doc hates that is used to designate `handedness’ for sugars and amino acids Fischer’s D and L notation What is the `I haz a happee’ modern way to designate handedness (which we learn today…) Prelog-Cahn-Ingold R and S notation (for all chiral species)

Chance favors the _________________________ prepared mind Quicky review (continued) Chance favors the _________________________ prepared mind