[1,3]-Sigmatropic Rearrangements of Divinylcyclopropane Derivatives and Hetero Analogs in Competition with Cope-Type Rearrangements – A DFT Study
✍ Scribed by Dirk Sperling; Hans-Ulrich Reißig; Jürgen Fabian
- Publisher
- John Wiley and Sons
- Year
- 1999
- Tongue
- English
- Weight
- 281 KB
- Volume
- 1999
- Category
- Article
- ISSN
- 1434-193X
No coin nor oath required. For personal study only.
✦ Synopsis
Two possible types of competing [1,3] rearrangements of hydroxy and formyl (donor and acceptor) groups in specific positions have also been considered. On the basis of these divinylcyclopropane derivatives and of the hetero-analogous compounds vinylcyclopropanecarbaldehyde and vinylcyclo-calculations, the [1,3] rearrangement of vinylcyclopropanecarbaldehydes to dihydrofurans can be expected to be propanecarbthioaldehyde to five-membered ring compounds have been investigated theoretically by (U)DFT (Becke3LYP/ kinetically favored over their conversion to cyclopentenes, while formation of the latter should be favored 6-31G*) methodology. Although both of the rearrangement pathways correspond to a reaction of the monosubstituted thermodynamically. This prediction is borne out by the experimental findings. Depending on the substitution cyclopropane substructure, i.e. a reaction of vinylcyclopropane or of cyclopropanecarb(thio)aldehyde, new features pattern, the [1,3]-sigmatropic rearrangement of vinylcyclopropanecarbaldehydes may compete with the [3,3]-in the reactivity are seen due to the combination of two substituents. Reaction parameters such as reaction and sigmatropic rearrangement. For the other investigated structures, the [1,3] rearrangement is strongly disfavored. activation energies of the [1,3]-sigmatropic rearrangements have been calculated and compared. Substituent effects of