Pericyclic or Pseudopericyclic? The Case of an Allylic Transposition in the Synthesis of a Saccharin Derivative

Abstract

When new concepts, models, or theories are introduced in a course, their presentation should be accurate, even if depth is not the goal. In a recent publication in this Journal, the Woodward–Hoffmann rules were invoked in the context of a new laboratory experiment, but the associated description was inaccurate. Here we aim to clarify the theoretical background relevant to the described laboratory experiment, and we describe a new computational experiment that could be used to further illuminate the relevant theoretical concepts.

The Computational Design of Two-Dimensional Materials

“…In addition to the mandatory experiments, students are required to design an independent computational project in consultation with the instructor. They may choose an experiment that has already been published in this journal (e.g., refs − ), design a project that is relevant to research projects they have carried out in experimental groups, or explore technical aspects of first-principles calculations. This allows students to focus on topics that are interesting to them and is relevant to their diverse backgrounds.…”

Reply to “Pericyclic or Pseudopericyclic? The Case of an Allylic Transposition in the Synthesis of a Saccharin Derivative”

“…Another obvious conclusion is that the reaction considered has a pseudopericyclic mechanism, as presented in Scheme . The Letter by Tantillo merely reports theoretical calculations, which can help to clarify the pseudopericyclic mechanism of the reaction and the Woodward–Hoffmann rules, while ignoring as it does the solvent polarity due to the presence of trimethylamine in the reaction medium and therefore disregarding the interaction energy between the ions in the pair.…”

“…This Journal published a paper describing a sequential synthesis of N -cinnamylsaccharin in which the last step was a [1,3] sigmatropic rearrangement . That paper was a subject of a recently published Letter criticizing the introduction of a sigmatropic rearrangement in the undergraduate curriculum and the allegedly inaccurate explanation of its mechanism …”

“…1 That paper was a subject of a recently published Letter criticizing the introduction of a sigmatropic rearrangement in the undergraduate curriculum and the allegedly inaccurate explanation of its mechanism. 2 The present letter explains the reasons why the [1,3] sigmatropic rearrangement experiment was proposed as a laboratory session for undergraduate organic students and discusses the mechanism of this reaction.…”

Rhodium-Catalyzed Ring Expansion Reactions for the Concise Construction of Densely Functionalized Oxathionines and Oxathiocines

“…From a structural point of view, the migrating C­(Ph)C group in TS-3 points toward the S and O atoms, with calculated S–C and C–O distances of 2.06 Å, and 1.86 Å, respectively. The natural bond orbital (NBO) analysis of TS-3 indicated the pseudopericyclic nature of this [1,4]-sigmatropic rearrangement process, (see Figure S3). On the other hand, for the [Rh]-bound ylide mechanism, all attempts to locate the [1,4]-shifted TS were unsuccessful.…”