Predict the major products of the following reactions, and propose mechanisms to support your predictions.

a. pent-1-ene + HCl

Predict the major products of the following reactions, and propose mechanisms to support your predictions.

b. 2-methylpropene + HCl

When 1 mole of buta-1,3-diene reacts with 1 mole of HBr, both 3-bromobut-1-ene and 1-bromobut-2-ene are formed. Propose a mechanism to account for this mixture of products.

When 1-chlorocyclohexene reacts with HBr, the major product is 1-bromo-1-chlorocyclohexane. Propose a mechanism for this reaction, and explain why your proposed intermediate is more stable than the other possible intermediate

Predict the major products of the following reactions, and propose mechanisms to support your predictions.

(b)

HINT: Remember to write out complete structures, including all bonds and charges, when writing a mechanism or determining the course of a reaction.

Show how you would accomplish the following synthetic conversions.

(a) but−1−ene → 1−bromobutane

(b) but−1−ene → 2−bromobutane

Show how you would accomplish the following synthetic conversions.

(c) 2−methylcyclohexanol → 1−bromo−1−methylcyclohexane

Show how you would accomplish the following synthetic conversions.

(d) 2−methylbutan-2-ol → 2-bromo-3-methylbutane

Propose a mechanism to show how 3,3-dimethylbut-1-ene reacts with dilute aqueous H₂SO₄ to give 2,3-dimethylbutan-2-ol and a small amount of 2,3-dimethylbut-2-ene.

HINT: When predicting products for electrophilic additions, first draw the structure of the carbocation (or other intermediate) that results from electrophilic attack.

Predict the products of the following hydration reactions.

a. 1−methylcyclopentene + dilute acid

Predict the products of the following hydration reactions.

b. 2-phenylpropene + dilute acid

c. 1-phenylcyclohexene + dilute acid

a. Propose a mechanism for the following reaction.

b. Give the structure of the product that results when this intermediate is reduced by sodium borohydride.

Predict the major products of the following reactions.

a. 1-methylcyclohexene+ aqueous Hg(OAc)₂

b. the product from part (a), treated with NaBH₄

Predict the major products of the following reactions.

c. 4−chlorocycloheptene + Hg(OAc)₂ in CH₃OH

d. the product from part (c), treated with NaBH₄

Show how you would accomplish the following synthetic conversions.

a. but-1-ene → 2-methoxybutane

b. 1-iodo-2-methylcyclopentane → 1-methylcyclopentanol

Show how you would accomplish the following synthetic conversions.

c. 3-methylpent-1-ene → 3-methylpentan-2-ol

Explain why acid-catalyzed hydration would be a poor choice for the reaction in (c).

Predict the major products of the following reactions.

a. propene + BH₃⋅THF

b. the product from part (a) + H₂O₂/OH⁻

Predict the major products of the following reactions.

(c) 2-methylpent-2-ene + BH₃⋅THF

(d) the product from part (c) + H₂O₂/OH⁻

Show how you would accomplish the following synthetic conversions.

a. but-1-ene → butan-1-ol

Show how you would accomplish the following synthetic conversions.

(b) but-1-ene → butan-2-ol

Show how you would accomplish the following synthetic conversions.

c. 2-bromo-2,4-dimethylpentane → 2,4-dimethylpentan-3-ol

In the hydroboration of 1-methylcyclopentene shown in Solved Problem 8-3, the reagents are achiral, and the products are chiral. The product is a racemic mixture of trans-2-­methylcyclopentanol, but only one enantiomer is shown. Show how the other enantiomer is formed.

Predict the major products of the following reactions. Include stereochemistry where applicable.

(a) 1−methylcyclohexene + BH₃⋅THF then H₂O₂, OH^–

Predict the major products of the following reactions. Include stereochemistry where applicable.

(b) trans-4,4-dimethylpent-2-ene + BH₃⋅THF then H₂O₂, OH^–

Predict the major products of the following reactions. Include stereochemistry where applicable.

(c)

When (Z)-3-methylhex-3-ene undergoes hydroboration–oxidation, two isomeric ­products are formed. Give their structures, and label each asymmetric carbon atom as (R) or (S). What is the relationship between these isomers?

When (E)-3-methylhex-3-ene undergoes hydroboration–oxidation, two isomeric products are formed. Give their structures, and label each asymmetric carbon atom as (R) or (S). What is the relationship between these isomers? What is the relationship between the products formed from (Z)-3-methylhex-3-ene and those formed from (E)-3-methylhex-3-ene?

Show how you would accomplish the following transformations.

(a)