1. (4 pts) Draw structures corresponding to each of the following.
a) (R)-3,4-dimethyl-2-hexyne
b) a chiral alkene of formula C7H14
2. (8 pts) Assign R or S configuration to each stereocenter in the molecules below.
3. (3 pts) Place an asterisk (*) at each of the stereogenic centers in the molecule below.
4. (4 pts) The enzyme aconitase catalyzes the hydration (addition of H2O) of aconitic acid to form two products, citric acid and isocitric acid. Isocitric acid is optically active; citric acid is achiral and optically inactive.
Draw the structure of citric acid
5. (9 pts) Label each pair of stereoisomers below as:
A. enantiomers
B. diastereomers
C. identical meso compounds
D. identical
Place the letter of your answer in the blank
a)__________
b)__________
c)__________
6. (15 pts) Predict the major organic products in each reaction below. If more than one major product is expected, draw each of them. Be sure to indicate stereochemistry when appropriate.
a)
b)
c)
d)
e)
7. (9 pts) For each reaction below, indicate the reagents necessary to produce the indicated product.
a)
b)
c)
8. Consider the reaction below to answer the following questions.
Careful separation of the dichlorobutane products from this reaction resulted in five pure isomeric compounds of formula, C4H8Cl2.
a) (10 pts) Draw the structures for these five products in the boxes labeled A - E below. Be sure to show all stereochemistry clearly
| A
|
B | C |
| D
|
E |
b) (10 pts) For each of the above five structures, indicate below each structure whether it is chiral or achiral.
c) (3 pts) Draw the structure of reactive intermediate generated from the starting material that results in the formation of one of the products A - E.
9. (4 pts) Draw curved arrows to show the electron flow in the reaction mechanism for the following reactions.
10. (12 pts) Carbon-carbon bond-forming reactions are important reactions in organic synthesis. Starting with any organic reagents of four or fewer carbons and any inorganic reagents needed, show two different preparations for the compound below using a different type of C-C bond forming reaction for each synthesis. Show all reagents and the stable intermediate structures formed in each separate reaction.
Synthesis a)
Synthesis b)
11. (6 pts) Consider the structure shown in the box labeled B below. In box A, draw a structure of lower oxidation state and in box C, draw a structure of higher oxidation state.
| A
|
B
|
C |
|
lower oxidation state |
higher oxidation state |
12. (3 pts) Draw a Fischer projection for the following compound.
