16841-46-6Relevant academic research and scientific papers
Multigram scale synthesis of 3,4- and 3,6-dihydro-2H-thiopyran 1,1-dioxides and features of their NMR spectral behavior
Chabanenko, Roman M.,Yu. Mykolenko, Svitlana,Kozirev, Eugene K.,Palchykov, Vitalii A.
supporting information, p. 2198 - 2205 (2018/07/15)
A new four-step synthesis of 3,4- and 3,6-dihydro-2H-thiopran-1,1-dioxides from dihydro-2H-thiopyran-3(4H)-one is reported. The title compounds are synthesized starting with oxidation of the ketone with a 30% aqueous solution of hydrogen peroxide in a mixture of AcOH-Ac2O. The keto group is then reduced by sodium borohydride followed by mesylation and elimination of methanesulfonic acid under basic conditions (pyridine for 3,4-isomer and aqueous NaOH for 3,6-isomer). This sequence is simpler, than previously known methods, uses cheaper and more readily available reagents, and leads to 2H-thiopran-1,1-dioxides on multigram scale with 64% and 74% total yields, respectively. The structure and purity of the compounds were confirmed by 2D NMR and GCMS methods. The proposed method expands the means to access functionalized cyclic sulfones as building blocks in the synthesis of combinatorial libraries of new biologically active compounds.
SENSITIZED PHOTOCYCLODIMERIZATION OF α,β-UNSATURATED CYCLIC SULFONES. CRYSTAL STRUCTURAL ANALYSES OF THE PHOTODIMERS OF 2-SULFOLENE AND THIA-2-CYCLOHEXENE-1,1-DIOXIDE
Kuhn, Hans Jochen,Defoin, Rosalie,Gollnick, Klaus,Krueger, Carl,Tsay, Yi-Hung,et al.
, p. 1667 - 1678 (2007/10/02)
The reactivity of five- and six-membered unsaturated cyclic sulfones in sensitized photocyclodimerization depends on position and substitution of the double bond.Thus, 2-sulfolene (1) and its six-membered analogue thia-2-cyclohexene-1,1-dioxide (3) photodimerize to yield each three products, 5, 6, 7 and 9, 10, 11, respectively, of which only 7 and 10 are analogous.However, 3-methyl-2-sulfolene (1a), 3-sulfolene (2) and its 3-methyl derivative (2a), as well as thia-3-cyclohexene-1,1-dioxide (4) remain unchanged under the same conditions.Dimerization of 1 and 3 is also effected by γ-irradiation.Structure and stereochemistry of the six dimers were determined by crystal structural analyses.Except for 6, the main product of γ-radiation-induced dimerization of 1, all the other dimers (5, 7 and 9-11) are tricyclic cycloadducts with anti (transoid) configuration at the central cyclobutane ring. 6 is an unsaturated open-chain dimer with C-C and C-S bond contractions, the latter indicating conjugation of the double bond with the sulfone group.While the cyclobutane rings of 5 and 7 (from 1) are planar, those of all three dimers from 3 are folded: the 6.4.6 skeletons of two of them comprise one (11) or two (9) trans fusions.
