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- Thermal rearrangement of 3-allyloxy-1,2-benzisothiazole 1,1-dioxides: an unusual inversion of products of sigmatropic [3,3]-shift to give the [1,3]-IsomersPublication . Cristiano, Maria Lurdes Santos; Brigas, Amadeu; Johnstone, Robert A. W.; Loureiro, Rui M. S.; Pena, Paula C. A.3-Allyloxy-1,2-benzisothiazole 1,1-dioxides isomerize thermally to give [3,3]- and [1,3]-products 6 of sigmatropic shift, of which the former reacts further to give solely the [1,3]-isomer.
- Electronic effects on C-O-C ether bonds in 3-aryloxy derivatives of benzisothiazole 1,1-dioxides: rapid ethanolysis of 3-(4-nitrophenoxy)-1,2-benzisothiazole 1,1-dioxide, (1), to give 3-ethoxy-1,2-benzisothiazole 1,1-dioxide, (2)Publication . Brigas, A. F.; Gonçalves, P. M.; Johnstone, Robert A. W.The bond lengths in the central C-O-C ether linkage of title compound (1), C13H8N2O5S, are comparable with those found in earlier work on similar compounds. However, (1) was found to undergo very easy solvolysis with ethanol to give (2), C9H9NO3S, for which a structure was also determined, but 3-(4-methoxyphenoxy)-1,2-benzisothiazole 1,1-dioxide, (3), did not hydrolyse under the same conditions. If ground-state structures are important for solvolysis, these results suggest that there should be a difference in the corresponding C-O bond lengths for the ethers (1) and (3). Such differences are not observed. The results can be rationalized by supposing that transition-state energies for ethanolysis are more important factors than those of the ground state.