Lecture 12Outline of Last Lecture I. DiastereomerII. Overview of IsomersIII. Priority RulesIV. Assigning R or SV. Overview of ChiralityCHEM 333 1st EditionOutline of Current LectureI. Meso compoundII. Fischer ProjectionsIII. Properties of Stereoisomersa. Enantiomersb. Diasteriomersc. Nature is chiralI. Nuclephilic Substitution Reactionsa. Nucleophile (Nuc/Nu)b. ElectrophileCurrent LectureI. Meso compound: compound that has two or more chiral centers but is not chiral (has a plane of symmetry)a. Example:b. Example:1. Which are the enantiomers? A and C2. Which is the mesocompound? B3. List 2 diastereomers: A and B, B and Cc. Example:1. Draw as a mesocompound2. Draw as a chiral compound3. Draw the enantiomerI. Fischer Projections: 2-D representation (used to draw carbohydrates/sugars)a. Draw vertical bonds away from youb. Draw horizontal bonds towards youc. Example: glyceraldehyded. Example:e. Example:II. Properties of Stereoisomersa. Enantiomers: identical physical and chemical properties in a chiral environment (same melting point, same boiling point, pKa, solubility in water)b. Diasteriomers: can have different physical propertiesc. Nature is chiral (DNA/proteins/enzymes)i. Enzymes: workhorses and most common drug target. Have a “lock andkey mechanism.”ii. Two enantiomers can have different physiological propertiesII. Nuclephilic Substitution Reactions: any reaction wherea nucleophile replaces a leaving groupa. Nucleophile (Nuc/Nu): nucleus loving = electron donor = Lewis base = seeks a positive or partially positive center b. Electrophile: electron accepting = Lewis acid = electron lovingi. Example: ii.
View Full Document
Unlocking...