The Photoreversible Addition of Sulfur Dioxide to Benzobenzvalene: a New Approach to the Benzoprefulvene Biradical

Article Article scientifique Article The Photoreversible Addition of Sulfur Dioxide to Benzobenzvalene: a New Approach to the Benzoprefulvene Biradical eng 1990 author Burger Ulrich 25497 author Gmuender Christian Jacques 35436 author Schmidlin Serge Patrice 23822 author Bernardinelli Gérald Hugues 24765 1724-1729 10.1002/hlca.19900730617 0018-019X https://onlinelibrary.wiley.com/doi/10.1002/hlca.19900730617 Benzobenzvalene (naphthvalene; 1) is shown to add SO2 to a lateral bicyclobutane bond with formation of a sulfone 2 and a ‘γ-sultine' 3. The structure of the latter is unambiguously established by X-ray diffraction. Both adducts extrude SO2 upon direct photolysis at 254 nm and regenerate 1 accompanied by naphthalene in a 1:3 ratio. This result is interpreted in terms of a reversible homolytic cleavage leading, for both, 2 and 3, to the same sulfinyloxy biradical 5, which by loss of SO2 gives the benzoprefulvene biradical 6. The latter in its singlet state undergoes ring closure to 1, or it opens to give naphthalene. Dewey 540 Swiss National Science Foundation 20-27665.89 CH 36 Département de chimie organique 141 false Helvetica Chimica Acta 73 6 7733844b-9d56-4b21-bc57-db2ffaa94f53 Article (Published version) Restricted hlca.19900730617.pdf 725942 application/pdf restrictedAccess Faculté des sciences / Section de chimie et biochimie / Département de chimie organique

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The Photoreversible Addition of Sulfur Dioxide to Benzobenzvalene: a New Approach to the Benzoprefulvene Biradical	Helvetica Chimica Acta			1990	217	0

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Gmuender, Christian Jacques