94年私立大同大學生物工程所有機化學

(1) Give the ground-state electron configuration for carbon.

(2) How many electrons does carbon have in its valence shell? 
(3) What kind of hybridization do you expect for the indicated carbons in thefollowing molecules or species. 

(1) Which acid above will be almost completely deprotonated by NaOH? 
(2) Which acid has the strongest conjugate base? 
(3) Is tert-butoxide anion a strong enough base to react with water? 
(4) Explain why phenol has a much lower pKa than ethanol.

(1) Draw all isomers of C4H9Br, and name them. 
(2) Which are chiral? 
(3) Arrange them in order of decreasing reactivity in the SN2 reaction. 

(1) Draw a chair cyclohexane ring, and label all positions as axial orequatorial.

(2) Why is a cis-1,3-disubstituted cyclohexane more stable than its transisomer? Draw the most stable conformation of both, and explain.

Write the complete stepwise mechanism for the following reactions, showingthe structures of the intermediates and using curved arrows to indicate electronflow in each step.

Predict the products of the following reactions, indicating both regiochemistryand stereochemistry when appropriate:

(1) Assign R or S configuration to each chirality center indicated instreptimidone.
(2) Based on the number of chirality centers, how many stereoisomers ofstreptimidone are possible? 
(3) Which are enantiomers, and which are diastereomers? 
(4) Will streptimidone have a meso stereoisomer? Explain your answer. 

Predict the product(s) of the following reactions:

Identify the reagents represented by the letters a-e in the following scheme:

Show how the following conversions might be accomplished. Show allreagents and all intermediate structures. More than one step may be required.