91Ó°ÊÓ

Show the structures of alkenes that give the following products on oxidative cleavage within acidic solution:

Propose a curved-arrow mechanism to show how ozone (O₃) reacts

with a carbon–carbon double bond to form a molozonide, the first intermediate

in ozonolysis.

Which of the reactions below would result in a product mixture thatwould rotate plane-polarized light?

a)

Which of the reactions below would result in a product mixture thatwould rotate plane-polarized light?

b)

Which of the reactions below would result in a product mixture thatwould rotate plane-polarized light?

c)

Iodine azide, adds to alkenes by an electrophilic mechanism similar to that of bromine. If a monosubstituted alkene such as 1-butene isused, only one product results:

a) Add lone-pair electrons to the structure shown for, and draw a

second resonance form for the molecule.

Iodine azide,adds to alkenes by an electrophilic mechanism similar to that of bromine. If a monosubstituted alkene such as1-butene isused, only one product results:

b) Calculate formal charges for the atoms in both resonance structuresyou drew for,in part (a).

Iodine azide,, adds to alkenes by an electrophilic mechanism similar to that of bromine. If a monosubstituted alkene such as 1-butene is used, only one product results:

c)

In light of the result observed when,adds to 1-butene, what is

the polarity of thebond? Propose a mechanism for the reaction

using curved arrows to show the electron flow in each step.

10-Bromo-a-chamigrene, a compound isolated from marine algae, isthought to be biosynthesized from g-bisabolene by the following route:

Draw the structures of the intermediate bromonium and cyclic carbocation,and propose mechanisms for all three steps.

Isolated from marine algae, prelaureatin is thought to be biosynthesized from laurediol by the following route. Propose a mechanism