S1 Supporting information Addition of phenoxathiin cation radical to alkenes and non-conjugated dienes. Formation of (E)- and (Z)-(10-phenoxathiiniumyl)alkenes and (E)- and (Z)-(10- phenoxathiiniumyl)dienes on basic alumina. Bing-Jun Zhao, * , † Henry J. Shine, * , † John N. Marx, † Cristina Hofmann, ‡ and Kenton H. Whitmire ‡ † Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas 79409, USA and ‡ Department of Chemistry, Rice University, Houston, Texas 77005, USA henry.shine@ttu.edu/bingjunz@yahoo.com Fax: 806-742-1289 1. 1 H and 13 C NMR data of compounds 6b-6g, 7b-7i, 9b-9g, 10a-10h, 8a, c, d, 14a, 13c, d---------------------------------------------------------------------S2-S5 and S7-S11 2. Preparation of (10-phenoxathiiniumyl)alkenes from 6b-6g and 7a-c, f, h, i--------- ------------------------------------------------------------------------------------------S5-S7 3. X-ray Crystallography: Figures S1, S2, Ortep diagrams for compounds 6c, 9a----- ----------------------------------------------------------------------------------------S12-S13 4. 1 H and 13 C NMR spectra of compounds 6a, 7a, 8a, 9c, 10f, 13c------------S14-S42