Reversible Disulfur Monoxide (S<sub>2</sub>O)-Forming Retro-Diels−Alder Reaction. Disproportionation of S<sub>2</sub>O to Trithio-Ozone (S<sub>3</sub>) and Sulfur Dioxide (SO<sub>2</sub>) and Reactivities of S<sub>2</sub>O and S<sub>3</sub>
作者:Juzo Nakayama、Satoshi Aoki、Jun Takayama、Akira Sakamoto、Yoshiaki Sugihara、Akihiko Ishii
DOI:10.1021/ja047729i
日期:2004.7.1
(5b) quantitatively. The thermally labile 5 was shown to undergo a retro-Diels-Alder reaction that produces S(2)O and 3 in a reversible way. The resulting S(2)O was trapped by Diels-Alder reactions with dienes to give 3,6-dihydro-1,2-dithiin 1-oxides in good yields. In the absence of the dienes, S(2)O disproportionates to SO(2) and S(3), and the resulting S(3) underwent a 1,3-dipolar cycloaddition with
5,6-二叔丁基-2,3,7-trithiabicyclo[2.2.1]hept-5-ene 7-endo-oxide (4) 通过将 S(2)Cl(2) 添加到 3 制备,4-二叔丁基噻吩 1-氧化物 (3) 收率高。4 用二甲基二环氧乙烷氧化得到 7:1 的 5,6-二叔丁基-2,3,7-trithiabicyclo[2.2.1]hept-5-ene 2-endo-7-endo-dioxide 的异构混合物(5a) 和 2-exo-7-endo-dioxide (5b)。热不稳定 5 被证明经历逆狄尔斯-阿尔德反应,以可逆的方式产生 S(2)O 和 3。由此产生的 S (2) O 被困通过 Diels-Alder 反应与二烯以良好的产率得到 3,6-dihydro-1,2-dithiin 1-氧化物。在没有二烯的情况下,S(2)O 与 SO(2) 和 S(3) 不成比例,由此产生的 S(3)