It is to be determined whether the addition of a nucleophile to the O atom of a C=O group is allowed or forbidden. Concept introduction: In nucleophilic addition step, the nucleophile adds to the polar π bond. The nucleophile is relatively electron rich, and the polar π bond is relatively electron poor. Thus, the curved arrow drawn from the nucleophile to the polar π bond represents the flow of electrons from an electron-rich site to an electron-poor site. The nucleophile is an electron-rich site, and the carbon of carbonyl carbon C=O is an electron-poor site. Thus, the relevant HOMO will be contributed by the nucleophile, and the relevant LUMO will be contributed by the C=O group. The highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) must have axial overlap or parallel overlap. The axial overlap between HOMO and LUMO has substantial net overlap, so this reaction is allowed. If the HOMO and LUMO do not have a substantial overlap, this overlap is forbidden.

Question

Want to see the full answer?

Answer 1

Question

Chapter D, Problem D.10P

Interpretation Introduction

Interpretation:

It is to be determined whether the addition of a nucleophile to the O atom of a C=O group is allowed or forbidden.

Concept introduction:

In nucleophilic addition step, the nucleophile adds to the polar π bond. The nucleophile is relatively electron rich, and the polar π bond is relatively electron poor. Thus, the curved arrow drawn from the nucleophile to the polar π bond represents the flow of electrons from an electron-rich site to an electron-poor site.

The nucleophile is an electron-rich site, and the carbon of carbonyl carbon C=O is an electron-poor site. Thus, the relevant HOMO will be contributed by the nucleophile, and the relevant LUMO will be contributed by the C=O group. The highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) must have axial overlap or parallel overlap. The axial overlap between HOMO and LUMO has substantial net overlap, so this reaction is allowed. If the HOMO and LUMO do not have a substantial overlap, this overlap is forbidden.

Expert Solution & Answer

Want to see the full answer?

Check out a sample textbook solution

See solution

Students have asked these similar questions

Draw the most stable cations formed in the mass spectrometer by a deavage of the following compound Draw the most stable cations formed in the mass spectrometer by a cleavage of the following compound он

Curved arrows are used to illustrate the flow of electrons. Using the provided starting anand product sytucutrs, draw the curved electron-pusing arrows for the following reaction or mechanistic steps. Be sure to account for all bond-breaking and bind-making steps

Draw the major elimination and substitution products formed in this reavtion. Use a dash or wedge bond to indicatr the stereochemistry of substituents on assymetric centers, wheere applicable. Ignore any inorganic byproducts.