Ochem Exam 3 (Quiz 7&8)

B

What point on the reaction energy diagram below best indicates the position of the transition state for the reaction?

(R,E)-2,4-dibromo-3-methylpent-2-ene

Name the following compound:

(R,E)-3-chlorohex-4-en-1-yne

Name the following compound:

(R,Z)-5-benzyloct-5-en-3-ol

Name the following compound:

(S,E)-3-methyl-5-phenyl-3-heptene

Name the following compound:

(S,Z)-3-bromo-4-methylhex-2-ene

Name the following compound:

(Z)-3-methoxyhex-3-ene

Name the following compound:

II

What is the final product of the following synthesis?

None of these choices.

What is the major product for the following reaction sequence?

none of these choices

What is the major product for the following reaction?

None of these choices.

What is the major product of the following reaction sequence?

none of these choices

What is the major product of the following reaction sequence?

D

What is the major product of the reaction given below?

(CH3)3C-CH=CH2

What is the major product of the reaction,

II and IV

What is the product(s) formed by treating 3,3 dimethylcyclopentene with H3O+ and heating?

equal mixture of A and B

What is the product(s) of the reaction below?

Elimination reactions are favored over nucleophilic substitution reactions

in all of these cases.

Which is not a satisfactory procedure for the synthesis of 3-methyl-1-butene?

(CH3)2CHCHOHCH3 + conc. H2SO4

Your task is to convert 2-bromobutane to 1-butene in highest yield. Which reagents would you use?

(CH3)3COK/(CH3)3COH

Which alkene would yield only CH3CH2COOH on oxidation with hot alkaline potassium permanganate (followed by acid work-up)?

(E)-3-hexene

An alkene with the molecular formula C8H16 undergoes ozonolysis to yield a mixture of (CH3)2C=O and (CH3)3CCHO. The alkene is:

2,4,4-Trimethyl-2-pentene

Which of the following reductions of an alkyne is NOT correct?

2-Pentyne + Li/NH3(l) → Z-2-Pentene

One mole of an optically active compound, X, with the molecular formula C6H8 reacts with three moles of hydrogen in the presence of a catalyst to yield an optically inactive product that cannot be resolved. X also exhibits IR absorption at approximately 3300 cm-1. Which is a possible structure for X?

3-methyl-1-penten-4-yne

An unknown compound, B, has the molecular formula C7H12. On catalytic hydrogenation 1 mol of B absorbs 2 mol of hydrogen and yields 2-methylhexane. B has significant IR absorption band at about 3300 and 2200 cm-1. Which compound best represents B?

5-methyl-1-hexyne

III

A compound, C6H10, which reacts with 2 mol of hydrogen over a platinum catalyst and which shows an IR absorption band at approximately 3300 cm-1 could be:

(Z)-3-(1-methylethyl)-5-methyl-2-hexene

A correct IUPAC name for the following compound is:

I and II

Addition of hydrogen chloride to the following molecule would produce:

Which of the following could be used as the basis for a simple test that would distinguish between 1-pentyne and pentane?

All of these choices.

III

An alkene with the molecular formula C10H18 is treated with ozone and then with zinc and acetic acid. The only product isolated from these reactions is:

V

An optically active compound, A, with the molecular formula C7H12 reacts with cold dilute KMnO4 and gives IR absorption at about 3300 cm-1. On catalytic hydrogenation, A is converted to B (C7H16) and B is also optically active. Which is a possible structure for A?

V

An unknown compound X was subjected to ozonolysis and was found to the following products. Determine which of the following compounds listed below could be the unknown X?

Which reaction sequence would convert cis-2-butene to trans-2-butene?

Br2/CCl4; then 2 NaNH2; then Li/liq. NH3

E2

By analyzing the starting material and the product(s), the following reaction is an example of what type of mechanism?

SN2

By analyzing the starting material and the product(s), the following reaction is an example of what type of mechanism?

Addition of 2 mol of HCl to 1-butyne would yield:

CH3CH2CCl2CH3

An optically active compound, Y, with the molecular formula C7H12 gives a positive test with cold dilute KMnO4 and shows IR absorption at about 3300 cm-1. On catalytic hydrogenation, Y yields Z(C7H16. and Z is also optically active. Which is a possible structure for Y?

CH3CH2CH(CH3)CH2C≡CH

Reaction of sodium ethoxide with 1-bromopentane at 30°C yields primarily:

CH3CH2CH2CH2CH2OCH2CH3

V

Compound C has the molecular formula C7H12. On catalytic hydrogenation, 1 mol of C absorbs 1 mol of hydrogen and yields a compound with the molecular formula C7H14. On ozonolysis and subsequent treatment with zinc and acetic acid, C yields only:

Which reaction would yield a racemic product?

Cyclopentene + Br2/H2O →

III

Determine a possible structure for an alkene, X, formula C9H14, on the basis of the following information: X adds one mole of hydrogen on catalytic hydrogenation. On treatment with hot basic KMnO4 followed by acidification, X yields the following dicarboxylic acid.

product

For the reaction energy diagram below, what structure would be present at point C in the reaction mechanism?

I, II, V

Heats of hydrogenation data would be useful in comparing the relative stabilities of which of the following substances?

Equal amounts of I and II.

Hydroxylation of cis-2-pentene with cold alkaline KMnO4 yields

Addition of excess HCl to 2-methyl-3-heptyne would produce: I 2-methyl-3,3-dichloroheptane II 2-methyl-2,3-dichloroheptane III 2-methyl-4,4-dichloroheptane IV 2-methyl-3,4-dichloroheptane V 2-methyl-3-chloroheptene

I and III

Compound A: Z Compound B: Z Compound C: Z Compound D: E

Indicate whether the alkenes below have either the E or Z configuration.

(E)-4-phenylpent-3-en-1-ol

Name the following compound:

A compound X with the formula C7H10 undergoes catalytic hydrogenation to produce a compound Y with the formula C7H14. What could be true of X?

More than one of these choices.

Which of the following methods could be used to synthesize 4,4-dimethyl-2-hexyne?

More than one of these choices.

(E)-2-methylhex-2-en-4-yn-1-ol

Name the following compound:

II

Neopentyl alcohol, (CH3)3CCH2OH, cannot be dehydrated to an alkene without rearrangement. What is the chief product of dehydration?

What is the major product for the following reaction sequence? Cl Cl-> 1a. NaNH2 (excess) mineral oil, heat 1b. NH4Cl 2. H2 (excess), Pd/C

None of these choices.

IV

On hydrogenation with platinum, a compound C9H12 absorbs 2 mol of hydrogen. Which of the following is a possible structure for the compound?

II

Ozonolysis of compound Z yields the products shown below. What is the structure of Z?

only V

Predict the major organic product(s) of the following reaction:

none of these choices

Rank the following compounds from lowest to highest heat of hydrogenation:

III

Select the structure of the major product formed in the following reaction.

IV

Select the structure of the major product formed in the following reaction.

t-butoxide, t-butanol

Suggest a reagent to perform the following transformation:

4,5-Dimethyl-3-propyl-1-hexene

The correct IUPAC name for the following compound is:

4-Bromo-2-ethyl-1-pentene

The correct IUPAC name for the following compound is:

E2

The product(s) for the following reaction would mainly be dictated by which mechanism?

II and III

The reaction of Br2/CCl4 to cyclohexene would produce the compound(s) represented by structure(s):

IV

Treating 1-methylcyclohexene with H3O+ would yield primarily which of these?

IV, V

Upon catalytic hydrogenation with platinum, a compound C6H6 absorbs four moles of hydrogen. Select a structure for C6H6.

Two of these choices.

What are possible products for the following reaction?

I and II

What are the major product(s) formed when cis-1-bromo-2-methylcyclohexane reacts with sodium isopropoxide in isopropanol?

II

What are the major product(s) formed when trans-1-bromo-2-methylcyclohexane reacts with sodium isopropoxide in isopropanol?

II

What product would you expect from addition of deuterium chloride to 2-cyclohexyl-4-methyl-2-pentene?

II

What would be the major product of the following reaction?

I

What would be the major product(s) of the following reaction?

I and II

What would be the major product(s) of the following reaction?

IV

What would be the major product(s) of the following reaction?

IV

What would you expect to be the chief organic product(s) when tert-butyl bromide reacts with sodium acetylide, i.e.,

Zaitsev's rule states that:

When a reaction forms an alkene, and several possibilities exist, the more (or most) stable isomer is the one which predominates.

II

Which alcohol would be most easily dehydrated?

III

Which alkene would you expect to be the major product of the following dehydration?

E1

Which mechanism best describes the chemical process shown below?

III

Which of the following compounds could be produced from the following reaction sequence?

II

Which one of the following alcohols would dehydrate most rapidly when treated with sulfuric acid?

4-methyl-1-pentene

Which substance would undergo the following reaction?

Markovnikov addition of HI to 2-methyl-2-butene involves:

formation of a carbocation at C-2.

Which of the following reactions of cyclobutene would yield a meso product?

reaction with D2, Pt