organic chemstry

HW 8 Answer the following questions 1) Which of the following is the strongest acid?

2) Draw the resonance hybrid for the compound whose resonance contributors are shown below.

3) Draw all possible resonance contributors for the following species:

4) Draw the resonance contributors for the following species:

5) How many allylic hydrogens does the following compound have?

A) 2 B) 3 C) 4 D) 5 E) zero 6) Which of the following shows the correct relative stabilities of carbocations? A) 3° allylic > 2° > 1° benzylic B) methyl > 2° benzylic > 3° C) 3° benzylic > vinyl > 1° D) 2° allylic > 2° > vinyl E) 1° benzylic > 3° > 3° allylic 7) What is the major product of the following reaction?

A) I B) I and III C) II D) II and III E) III

8) List the following compounds in order of decreasing acidity.

9) What are the major products of the following reaction?

A) I only B) II only C) III only D) I and II E) I and III 10) What compound is formed from the 1,4-addition of one equivalent of HBr to 1,3-butadiene? A) 1-bromo-1-butene B) 2-bromo-2-butene C) 4-bromo-1-butene D) 3-bromo-1-butene E) 1-bromo-2-butene

11) Draw the major products of the following reaction:

12) What is the major product of the following reaction?

A) II Minor, III Major B) II Major, III Minor C) III only D) I and II E) II and III 13) What is the major product of the following reaction?

A) I only B) II only C) III only

D) I and II E) II and III 14) Draw the major product that is formed when the diene shown below reacts with HBr at -80 °C.

15) What is the product of the following reaction?

A) I B) II C) III D) IV E) V

16) Which of the following statements is true about a Diels-Alder reaction? A) The reaction works best when the dienophile contains an electron-withdrawing group conjugated to its C C. B) Substituents that are cis in the dienophile remain cis in the product. C) Dienes that cannot achieve an s-cis conformation do not react in Diels-Alder reactions. D) When the dienophile has a substituent with π electrons, the endo product is favored over the exo product. E) all of the above

17) What diene and what dieneophile should be used to prepare the following compound?

18) Draw the major product of the following reaction:

19) What diene and dienophile will react to form the compound shown below?

20) What diene and dienophile should be used to synthesize the compound shown below?