CHEM 140A Chapter Notes - Chapter 5: Meso Compound, Stereoselectivity, Fractional Distillation
19 Mar 2018
School
Department
Course
Professor
Document Summary
Compounds that have identical molecular formulas but differ in the order in which the individual atoms are connected. Atoms are connected in the same order but differ in their spatial arrangement. Chiral molecules cannot be superimposed on their mirror images. Each isomer of the image-mirror pair is called an enantiomer. All chiral examples contain an atom that is connected to four different groups. The symmetry in molecules helps to distinguish chiral structures from achiral ones. 5. 3 absolute configuration: r,s sequence rules x-ray diffraction can establish the absolute configuration. There is no straightforward correlation between the sign of rotation and the structure of the particular enantiomer. Rank all substituents in the order of decreasing priority. Position molecule so the lowest priority substituent is in the back. If the progression from highest to lowest is counterclockwise, the stereocenter is s. textbook notes page 1 the stereocenter is s. If the progression is clockwise, it is labeled r.
