2,2,4,4-Tetrakis(trifluoromethyl)-1,3-dithietane (1) reacts with quadricyclane (2) without a catalyst at ambient or elevated temperature, giving the corresponding cycloadduct, 3-thia-4,4-bis(trifluoromethyl)tricyclo[5.2.1.0 2,5 ]non-7-ene (3) in 74% yield. Similar reaction of 2,2,4,4-tetrafluoro-1,3-dithietane (4) at elevated temperature results in the formation of 3-thia-4,4-difuorotricyclo[5.2.1.0 2,5 ]non-7-ene (5a) along with two other byproducts. Both (n-C 4 F 9 S) 2 and [(CF 3 ) 2 CFS] 2 react with 2 upon heating (90–100°C) giving the corresponding nortricyclanes 9a,b and 11a,b in high yield. The reactions of CH 3 SO 2 Cl or CF 3 SO 2 Cl and 2 proceed at ambient temperature leading to mixture of isomeric nortricyclanes 13a,b and 15a,b. Reactions of quadricyclane reported here are apparently initiated by a single-electron transfer from quadricyclane to neutral substrates, the first such observed for an alkane.