Tetrahedron letters

Thiaozonide formation by singlet oxygen cycloaddition to 2, 5-dimethylthiophene

K Gollnick, A Griesbeck

Index: Gollnick, Klaus; Griesbeck, Axel Tetrahedron Letters, 1984 , vol. 25, # 43 p. 4921 - 4924

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Citation Number: 16

Abstract

Abstract Singlet oxygen reacts with 2, 5-dimethylthiophene (1) exclusively by (4+ 2)- cycloaddition to yield the thiaozonide 2. The structure of this product is inferred from its 1 H- and 13 C NMR spectra. Neat thiaozonide 2 decomposes violently at room temperature. In aprotic non-polar and in protic polar solvents it is slowly transformed into cis-sulfine 3c and cis-2, 5-dione 4c, which rearranges to the trans-isomer 4t. A mechanism for the ...