Exam 30: Orbitals and Organic Chemistry: Pericyclic Reactions

Exhibit 30-9 Vitamin D₃,cholecalciferol,is synthesized under the skin by the photochemical pericyclic process shown below.Answer the following question(s) about these reactions. -Refer to Exhibit 30-9.The second step in this process is a(n):

Exhibit 30-1 To answer the following question(s),consider the π molecular orbitals of a conjugated diene shown below: -Refer to Exhibit 30-1.Which molecular orbital of a conjugated diene contains two nodes between nuclei?

There are three major classes of pericyclic reactions.Which of the following types of reactions is not an example of a pericyclic process?

Exhibit 30-4 Consider the reaction below to answer the following question(s): -Refer to Exhibit 30-4.What type of pericyclic reaction is involved in this transformation?

Exhibit 30-1 To answer the following question(s),consider the π molecular orbitals of a conjugated diene shown below: -Refer to Exhibit 30-1.Which molecular orbital of a ground-state conjugated diene is the highest occupied molecular orbital (HOMO)?

Exhibit 30-1 To answer the following question(s),consider the π molecular orbitals of a conjugated diene shown below: -Draw the product(s) you would expect to obtain from photochemical cyclization of (2Z,4E)-hexadiene.

Exhibit 30-6 Consider the reaction sequence below to answer the following question(s): -Refer to Exhibit 30-6.Explain the stereochemistry of product C.

Predict the product (including stereochemistry) when the following substance reacts under thermal conditions.

Classify the following reaction.

Exhibit 30-5 To answer the following question(s),consider the reaction below: -Refer to Exhibit 30-5.How many pairs of electrons are involved in this pericyclic reaction?

Classify the following reaction.

Consider the reaction given below. Which of the following is correct?

Exhibit 30-4 Consider the reaction below to answer the following question(s): -Refer to Exhibit 30-4.Would you expect this reaction to occur under photochemical or thermal conditions?

How many π MO's does the following compound have?

Exhibit 30-5 To answer the following question(s),consider the reaction below: -Refer to Exhibit 30-5.What type of pericyclic reaction is involved in this transformation?

Consider the following MO diagram for a conjugated triene. When irradiated with light of the appropriate wavelength,how many electrons will be in bonding MO's?

Exhibit 30-7 Consider the Sommelet-Hauser rearrangement below to answer the following question(s): -Refer to Exhibit 30-7.Would you expect the Sommelet-Hauser rearrangement to be antarafacial or suprafacial? Explain.

For an odd number of electron pairs (double bonds),for cycloadditions reactions which of the following rules is correct?:

Draw the structure of the product when the following substance reacts with maleic anhydride.Classify the reaction according to the number of π electrons that interact.Atoms other than carbon and hydrogen are labeled.

Exhibit 30-6 Consider the reaction sequence below to answer the following question(s): -Refer to Exhibit 30-6.Explain the stereochemistry of product B.