10. Addition Reactions

Predict the products of the following reactions.

(g) trans-2,3-epoxyoctane + H⁺, H₂O

(h) propylene oxide + methylamine (CH₃NH₂)

Propylene oxide is a chiral molecule. Hydrolysis of propylene oxide gives propylene glycol, another chiral molecule.

(a) Draw the enantiomers of propylene oxide.

(b) Propose a mechanism for the acid-catalyzed hydrolysis of pure (R)-propylene oxide.

Predict the major products of the following reactions, including stereochemistry.

f. trans-pent-2-ene + peroxyacetic acid in water

a. Propose a mechanism for the conversion of cis-hex-3-ene to the epoxide (3,4-­epoxyhexane) and the ring-opening reaction to give the glycol, hexane-3,4-diol. In your mechanism, pay particular attention to the stereochemistry of the intermediates and products.

b. Repeat part (a) for trans-hex-3-ene. Compare the products obtained from cis- and trans-hex-3-ene. Is this reaction sequence stereospecific?

Predict the major product when each reagent reacts with ethylene oxide.

(d) PhNH₂ (aniline)

(e) KCN (potassium cyanide)

(f) NaN₃ (sodium azide)

The following reaction resembles the acid-catalyzed cyclization of squalene oxide. Propose a mechanism for this reaction.

Predict the major products of the following reactions, including stereochemistry where appropriate.

(c) (2S,3R)-2-ethyl-2,3-dimethyloxirane + CH₃O^– / CH₃OH

(d) (2S,3R)-2-ethyl-2,3-dimethyloxirane + H⁺ / CH₃OH

Under the right conditions, the following acid-catalyzed double cyclization proceeds in remarkably good yields. Propose a mechanism. Does this reaction resemble a biological process you have seen? 

Predict the product(s) that would result when the alkenes are allowed to react under the following conditions: (vii) 1. mCPBA 2. H₂SO₄, H₂O

(d)

Predict the product(s) that would result when the alkenes are allowed to react under the following conditions: (vii) 1. mCPBA 2. H₂SO₄, H₂O

(k)

There are two mechanisms by which each of the two enantiomers can form in the reaction shown in Figure 9.37. Show them.

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Show an arrow-pushing mechanism for reactions 1–4 in Figure 9.37.

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Limonene is one of the compounds that give lemons their tangy odor. Show the structures of the products expected when limonene reacts with an excess of each of these reagents.

f. peroxyacetic acid in acidic water

Propose a mechanism for the following reaction.

Predict the major products of the following reactions.

b. trans-hex-3-ene + peroxyacetic acid (CH₃CO₃H) in water

c. 1-methylcyclohexene + MMPP in ethanol