110a Exam 2 Review Sheet—Fall Semester 2015
Review Session: Wednesday, September 30, 7:00 PM, SN Aud
Exam: Friday, October 2, 7:50 AM, SN Aud
Chapter 4:
IUPAC nomenclature for C10 branched alkanes, alkyl halides, alkenes, alkynes, and alcohols; fragment
names: propyl, isopropyl, sec-butyl, isobutyl, tert-butyl, pentyl, neopentyl; IUPAC nomenclature for
cycloalkanes, including cis- and trans- descriptors; IUPAC nomenclature for bicyclic alkanes; physical
properties of alkanes (VDW interactions, effect of branching on boiling point, alkanes with a “useful”
boiling point, density relative to water); thermochemical (combustion) analysis of ring strain and ring
strain trends for C3-C14 rings; conformational analysis; sigma bonds; ethane, Newman projections,
torsional strain and its origin, conformational isomers, room temperature picture of ethane, staggered
conformation, eclipsed conformation, 2.8 kcal/mol barrier in ethane; butane conformational analysis,
gauche vs. anti conformational isomers and free energy difference between them, repulsive VDW
interactions, room temperature picture of butane, reasons for different barrier heights (3.4 vs. 5.5) on
rotational trajectory of butane; origins of ring strain in cyclopropane, cyclobutane, and cyclopentane;
reasons for conformational flexing in cyclobutane and cyclopentane; preferred conformations of
cyclopentane; preferred (chair) conformation of cyclohexane, axial vs. equatorial bonds, interconversion
via ring inversion; conformational analysis of intermediates along the ring inversion trajectory- pick one
or two unfavorable interactions (e.g., torsional strain) for each, symmetry of the twist conformational
isomer; kinetics vs. thermodynamics; G° = -RTlnKeq; conformational analysis of substituted
cyclohexanes, 1,3-diaxial interactions (repulsive VDW interactions in the ring system); what is the
relationship between methylcyclohexane thermodynamic behavior and butane conformational analysis?;
reasons for increasing degree of equatorial preference for bromine, methyl, and tert-butyl substituents on
cyclohexane; trends in cyclohexyl halides; methods for synthesizing alkanes from alkenes-catalytic
hydrogenation & index of hydrogen deficiency.
Chapter 5:
stereoisomers, enantiomers, chirality, achirality, stereogenic center, chiral center, diastereomers, Van't
Hoff; Pasteur; tests for chirality, methods for differentiating enantiomers- optical activity, enzymes-how?; Assigning configuration and designating stereochemistry: the R/S system, the D/L system, the +/–
system, the d/l system. Specific rotation and enantiomeric excess; racemic mixtures; the thalidomide
story; chemical correlation as a means of assigning configuration; absolute and relative configuration;
understanding of how diastereomers have different physical properties; meso compounds; Fischer
projection formulae; optical resolution.