Abstract
Under strongly acidic conditions, the title compound 1 readily participates in several possible rearrangement pathways, affording a product distribution which is relative to the choice of solvent and acid catalyst. Thus, using chloroform or acetone as the solvents and HBr or HClO4 as the catalysts, compounds 2-4 have been isolated and fully characterised; in addition, compound 5 was identified in the reaction mixture and characterised by H-1 NMR spectroscopy. The reaction kinetics of the transformations have been studied by H-1 NMR spectroscopy, using deuterated chloroform or acetone as the NMR solvents. A key intermediate in the reaction mechanisms is the allylic carbocation 6, which rearranges to give the fused system 3; in the presence of bromide anions, the carbocation forms an ion-pair intermediate 7, leading to the formation of compounds 2, 4 and/or 5, depending on the solvent.
Original language | English |
---|---|
Pages (from-to) | 1405-1410 |
Number of pages | 5 |
Journal | Journal of the Chemical Society, Perkin Transactions 2 |
Volume | 1999 |
Issue number | 7 |
DOIs | |
Publication status | Published - Jul 1999 |
Keywords
- substitution-reactions
- para-nitrobenzoates
- solvent assistance
- solvolysis
- ion
- ethers
- carbon
- acetonitrile
- mechanism
- chloride