When it is strongly heated, ethyl diazoacetate decomposes to give nitrogen gas and a carbene. Draw a Lewis structure of the carbene.

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

a. trans-but-2-ene → trans-1,2-dimethylcyclopropane

Show how you would synthesize each compound using methylenecyclohexane as your starting material.

(g)

Propose mechanisms consistent with the following reactions.

(d)

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.

m. CHBr₃ and 50% aq. NaOH

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.