The acid-catalyzed hydration we learned here in Chapter 8 is reversible:

(e) How might you shift the equilibrium to the left?

The reaction of (E)-3-chlorohex-3-ene with HCl results in the selective formation of 3,3-dichlorohexane instead of 3,4-dichlorohexane. Explain this result.

In addition to radicals, anions, and cations, a fourth class of reactive intermediates is carbenes. A neutral species, the simplest carbene has a molecular formula of CH₂.

(a) Draw the Lewis structure of CH₂.

In addition to radicals, anions, and cations, a fourth class of reactive intermediates is carbenes. A neutral species, the simplest carbene has a molecular formula of CH₂.

(b) What are the hybridization and shape of the central carbon of CH₂?

In addition to radicals, anions, and cations, a fourth class of reactive intermediates is carbenes. A neutral species, the simplest carbene has a molecular formula of CH₂ .

(e) Carbenes have great synthetic utility, especially in the synthesis of cyclopropanes from alkenes. Based on your answers to (a)–(d), show a mechanism for the cyclopropanation of cyclohexene.

In addition to radicals, anions, and cations, a fourth class of reactive intermediates is carbenes. A neutral species, the simplest carbene has a molecular formula of CH₂.

(f) Cyclopropanation of (E)- and (Z)-3-methylhex-3-ene gives two different products. Rationalize this outcome.

In addition to radicals, anions, and cations, a fourth class of reactive intermediates is carbenes. A neutral species, the simplest carbene has a molecular formula of CH₂.

(h) Of the reactions studied here in Chapter 8, cyclopropanation is most similar to which?

Suggest an arrow-pushing mechanism that accounts for the formation of the following products.

(a)