3. Acids and Bases

Identify the arrow types that are shown in each of these arrow-pushing mechanisms.

(iv)

Given a reaction profile diagram with $y$-axis labeled as energy and $x$-axis labeled as reaction coordinate, which point(s) on the curve correspond to the transition state(s)?

Which statement best describes the purpose of drawing curved arrows in an organic reaction mechanism?

Which of the following best describes the difference between organic and inorganic intermediates in a reaction mechanism?

Which energy diagram best represents a two-step reaction mechanism with a high-energy intermediate?

We show in Chapter 20 that α , β-unsaturated ketones are electrophilic at C₄. Rationalize this observation.

For practice in recognizing mechanisms, classify each reaction according to the type of mechanism you expect:

1. Free-radical chain reaction

2. Reaction involving strong bases and strong nucleophiles

3. Reaction involving strong acids and strong electrophiles

(c)

Show an arrow-pushing mechanism that forms the product on the right from the reactant at left. Two arrows are necessary in each reaction.

(a)

Show an arrow-pushing mechanism that forms the product on the right from the reactant at left. Two arrows are necessary in each reaction.

(b)

Which of the following best describes the products formed from a two-step reaction sequence where 2-bromopropane reacts first with aqueous ${\mathrm{Na}}_{\mathrm{OH}}$ and then with concentrated $H_2\mathrm{SO}{4}_4$?

Which of the following best describes the mechanism for the reaction of $t_1-\mathrm{butyl} \mathrm{bromide}$ with aqueous $\mathrm{NaOH}$ to form $t_1-\mathrm{butanol}$?

Label the reactants in these acid–base reactions as Lewis acids (electrophiles) or Lewis bases (nucleophiles). Use curved arrows to show the movement of electron pairs in the reactions.

(d)

Identify the arrows shown by type and predict the product that should result.

(a)

Identify the electrophile and the nucleophile in each of the following reaction steps and then draw curved arrows to illustrate the bond-making and bondbreaking processes.

c.