the corresponding thione S-oxides 8f–h in isolated yields of 10–40%, together with the benzophenones 7f–h. 3,3-Dimethyl-1,2-dioxirane, generated in situ from the reáction of acetone and ‘oxone’(2KHSO5- KHSO4-K2SO4), transferred an oxygenatom to compounds 4a, f, g, i providing the thione S-oxides 8a, f, g, i in 29–97% yield.
Acid–base reactions of adamantanethione S -methylide and its spiro-1,3,4-thiadiazoline precursor
作者:Grzegorz Mloston、Rolf Huisgen
DOI:10.1016/s0040-4020(00)00988-1
日期:2001.1
The spiro-1,3,4-thiadiazoline 1 loses N2 at 45°C, and, as recently reported, the short-lived adamantanethione S-methylide (2) is an active 1,3-dipole. Interception of 2 by acids HX consists of CH2-protonation and ion recombination. Even 1 acts as HX vs 2 and—after electrocyclic ring opening of the anion (13 →15)—affords the dithioacetal C22H32N2S2 (14). The Δ3-thiadiazoline 1 is converted by base or
螺-1,3,4-噻二唑啉1在45°C时失去N 2,并且,最近报道,寿命短的金刚烷硫酮S-甲基化物(2)是活性的1,3-偶极子。酸HX对2的拦截由CH 2-质子化和离子重组组成。偶数1代表HX vs 2,并且在阴离子(13 → 15)经电环开环后,承担了二硫缩醛C 22 H 32 N 2 S 2(14)的作用。的Δ 3 -thiadiazoline 1通过碱或酸催化转化为Δ 2 -tautomer 21。氨基腙(25,26)从形成1点秒-胺。讨论了机理并阐明了结构。
Thiofenchone<i>s</i>-methylide and its spiro-1,3,4-thiadiazoline precursor
作者:Rolf Huisgen、Grzegorz Mloston、Albert Pröbstl
DOI:10.1002/hc.1022
日期:——
Spiro[fenchane-2,2′-(1,3,4)-thiadiazoline] (6), prepared from thiofenchone and diazomethane, extrudes N2 (t1/2 22 min, 46°C, toluene) and furnishes the S-methylide 7 which, in turn, closes the thiirane ring or else is intercepted by 1,3-cycloadditions to dipolarophiles (tetracyanoethylene, maleic anhydride, N-methyl-1,2,4-triazoline-3,5-dione, aromatic thioketones). When thiocarbonyl S-methylide 7
Singletoxygen oxidation of dialkyl thioketones yields the corresponding ketones and in some cases sulfoxides in varying amounts. Steric considerations on the reactive zwitterionic/diradical intermediates have been invoked to rationalise the product distribution.