STUFF2KNOW

EXAM 3, 22005

Old stuff
Organic chemistry is a cumulative subject. You will need a knowledge of functional groups, electronegativity, nucleophile, electrophile, leaving group, formal charge, Lewis structure, hybridization states and resultant bond angles, acid base rxns, kinetics.  Because our discussion of stereochemical analysis of rxns focused primarily on alkene addition, know the addition of HX, H₂ , X₂ , and OsO₄  to alkenes.

New stuff (All of GOB 3, beginning of GOB 4)
Chp. 6

1.  Know how to do DU calculation (not DUI).
2.  Be able to do the E-Z nomenclature system for alkenes.
 

Chp. 9
1. Know what enantiomers are, how to identify chiral  centers and determine the absolute configuration of  chiral centers.  Also know how to draw the 2nd  enantiomer given the first (both ways).  Know how to draw both enantiomers given a flat structure.  When do enantiomers behave  the same?  When do they behave differently and why?
2. What are diastereomers?  What are meso compounds?  How  many stereoisomers are possible for a given chiral  molecule?  Do diastereomers behave the same?    
3. When is a molecule optically active?  What’s  plane-polarized light?  Know the formula for  calculating specific rotation.  Know how to use in a qualitative sense (if the path length is doubled what happens to observed rotation?  what about specific rotation?)  What’s a racemic  mixture?
4. Be able to differentiate between all of the different  types of isomerism we’ve studied.
5. Be able to perform stereochemical analysis on the  following rxns:  alkene additions (HX, H₂, X₂,  hydroxylation, ) and substitutions (S_N2).
6.  Know how enantiomers and diastereomers behave in biological systems.  Why does FDA require homochirality for new pharmaceuticals?  Know the thalidomide story.
7.  How does resolution work?
8. Also know how prioritization rules can be used to  describe alkene stereochemistry.

Chp. 12
1. IR theory- know different types of vibrational  transitions, relationship of horizontal axis to energy,  relationship of vertical axis to dipole moment change  (also how is %T determined?).  Why are IR vibrations not  discrete lines?
2. IR interpretation- which part of the spectrum do we  usually interpret?  Know how to relate functional  groups to specific IR stretches (need working knowledge  not perfect number memorization).
3. Be able to apply above to actual problem solving (two flavors of problems, matching of spectra to molecules and proposing potential structures consistent with IR and molecular formula info).
4. Understand how conjugation can affect the carbonyl  stretching wavenumber and the rationale behind it.

Chp. 11
1. S_N2 rxn- mechanism, kinetics, stereochemistry, and  characteristics with respect to E⁺ structure, LG,  solvent, and Nu:^- structure.  Also synthetic aspects. We discussed this reaction in great detail and it will comprise a significant portion of the test.
 

Study hard over multiple days for best results on organic exams.  Practice mechanisms.  Make sure you are an expert at Lewis structures, formal charges, recognition of Nu:^-, E⁺, L.G., and curved arrow notation.  There are fewer rxns on this exam but need to know some of them in greater detail (stereochemical analysis, S_N2).    Look at your old quizzes, hmwks, and help session questions.  Remember, you enjoy studying chemistry, even over Thanksgiving break!  Feel free to come by with questions anytime or call me