What is the formal charge on the carbon of the following carbene?

Show how you would accomplish each of the following synthetic conversions.

(c)

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.

Suggest a mechanism for the reaction shown in Figure 16.30 using IZnCH₂I as the cyclopropanating reagent.

Two chemists at Dupont found that ICH₂ZnI is better than diazomethane at converting a C=C bond to a cylcopropane ring. Propose a mechanism for the reaction, now known as the Simmons–Smith reaction in their honor.

When dichloromethane is treated with strong NaOH, an intermediate is generated that reacts like a carbene. Draw the structure of this reactive intermediate, and propose a mechanism for its formation.

Dichlorocarbene can also be generated by heating sodium trichloroacetate. Propose a mechanism for the reaction.