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Dioxiranes: Synthesis and Reactions of Methyldioxiranes

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Dioxiranes: Synthesis and Reactions of Methyldioxiranes J. Org. Chem. 1985,50, 2847-2853 2847 30 min at -15 "C, about 60% of the SO2 was removed. The liquid that at 5.54 to collapse to a 4.5 Hz d. Anal. Calcd for was stirred into diethyl ether, the ether was decanted, and acetone C14H17N3011S2:C, 35.97; H, 3.67; N, 8.99. Found: C, 36.24; H, was added to yield upon filtration 29 g (85%) of 15. 3.54; N, 8.96. Preparation of 15 in CH2C12. To 70 g of CH2C12and 20 g 1-(2-Thienyl)tetrahydrothiopheniumPicrate (17). To 75 (0.23 mol) of THT at -30 "C was added 14 g (0.40 mol) of chlorine g of SO2 and 16 g (0.18 mol) of THT at -30 "C was added 21.7 followed by addition of 18.1 g (0.17 mol) of styrene. After 30 min, g (0.16 mol) of S02C12followed by 13.96 g (0.16 mol) of thiophene. the solution was stirred into ether, the ether was decanted, and After 30 min at -5 "C 30 mL of H20 was added and the SO2 was acetone was added to give 4.2 g (9.2%) of 15: 60-MHz 'H NMR removed. After extraction twice with both chloroform and hex- (D20)6 7.5 (5 H, b, phenyl), 5.48 [l H, t, J = 7 Hz, C(2) HI, 3.96 anol, the material was converted to the picrate by the usual [2 H, AB of ABX, J(AB) = 13 Hz, C(1) H2], 3.4 (4 H, m, width manner to give 9.3 g (14.6%) of 17: 100-MHz 'H NMR 20 Hz, THT+ a H), 2.14 (4 H, m, width 14 Hz, THT' /3 H); (Me2SO-d6)6 8.61 (2 H, s, picrate), 8.22 [lH, dd, J = 5.1 Hz, J' 60-MHz 'H NMR (CF,COOH) 6 7.5 (5 H, b, phenyl), 5.45 (1 H, = 1.4 Hz, C(5) HI, 8.00, [l H, dd, J = 3.8 Hz, J'= 1.4 Hz, C(3) t, J = 7 Hz), 3.85 (2 H, t, J = 7 Hz), 3.55 (4 H, m, width 25 Hz), HI, 7.34 [l H, dd, J = 5.1 Hz, J'= 3.8 Hz, C(4) HI, 3.88 (4 H, 2.36 (4 H, m, width 15 Hz). Anal. Calcd for C1,HI6Cl2s C, 54.76; m, width 60 Hz, THT+ a),2.39 (4 H, m, width 18 Hz, THT+ 8). H, 6.13; C1, 26.94. Found: C, 54.80; H, 6.25; C1, 25.80. Coupling constants among thiophene ring protons: J(3,4) = 3.8 [2-Chloro-l-[(4-chlorobutyl)thio]ethyl]benzene(15Rb) and Hz, J(3,5) = 1.4 Hz, J(4,5) = 5.1 Hz. Placement of the THT' [ 1-Chloro-2-[(4-chlorobutyl)thio]ethyl]benzene (15Ra). The ring at the 2-position on the thiophene ring is established by chloride salt 15 was heated gently in a test tube to 120 "C, causing similarity of the thiophene ring proton-proton coupling constants it to melt and resolidify to a water-insoluble and acetone-soluble to the corresponding values reported16 for unsubstituted product: 60-MHz 'H NMR (acetone-&) 6 7.35 (5 H, m, phenyl), thiophene, J(3,4) = 3.50 Hz, J(2,4;3,5) = 1.04 Hz, J(2,3;4,5) = 4.90 5.15 (0.7 H, t, J = 7.5 Hz), 4.00 (0.7 H, ABC pattern), 3.53 (2 H, Hz, J(2,5) = 2.84 Hz. Anal. Calcd for CI4Hl3O7N3S2:C, 42.10; t, J = 8 Hz), 3.21 (1.3 H, d, J = 7.5 Hz), 2.80 (0.4 H, t, J = 8 Hz), H, 3.28; N, 10.52. Found: C, 41.8; H, 3.33; N, 10.54. 2.50 (2 H, t, J = 8 Hz), 1.8 (4 H, m width 20 Hz). 1-(2-Hydroxytetrahydr0-3-furanyl)tetrahydro- Acknowledgment. We express our gratitude to the thiophenium Picrylsulfonate (16). To 70 g of SO2 and 20 g following people for valuable assistance on this project: D. (0.23 mol) of THT at -30 "C was added 26.7 g (0.20 mol) of S02C12 Urchick, H. B. Smith, and W. Jensen, Jr., for experimental followed by addition of 14 g (0.20 mol) of 2,3-dihydrofuran. After assistance; A. S. Knight and R. S. Malek for bioassay; D. 30 min at -15 "C about 2/3 of the SO2 was removed under vacuum, 50 mL of water was added, and the remaining SO2 was removed. Armentrout, J. T. Solc, N. E. Skelly, and D. Jensen for The aqueous solution was extracted with CH2C12and picrylsulfonic chromatography; J. C. Tou and G. J. Kallos for mass acid was added, giving 18.2 g (19.5%) of 16: 60-MHz 'H NMR spectrometry; R. A. Nyquist for infrared spectroscopy; T. (Me2SO-d6)6 8.82 (2 H, s, picrylsulfonate), 7.45 [l H, d, J = 4 E. Fisk, R. A. Kirchhoff, H. Small, and M. J. Hatch for Hz, C(2) OH], 5.54, [l H, t, J = 4 Hz, C(2) HI, 3.98 [3 H, m, incl consultation. J = 0.6 Hz, C(3) H and C(5) H2], 3.5 (4 H, m, width 15 Hz, THT' a),2.18 [6 H, m, width 20 Hz, C(4) H2 and THT+ PI. Smaller absorptions at 6 7.7, 4.6, and 3 are attributed to another com- (16) Brugel, W."Handbook of NMR Spectral Parameters"; Heyden ponent. Adding D20 caused the 6 7.45 signal to disappear and and Sons Inc.: Philadelphia, 1979; Vol. 3, pp 657. Dioxiranes: Synthesis and Reactions of Methyldioxiranes Robert W. Murray* and Ramasubbu Jeyaraman Department of Chemistry, University of Missouri-St. Louis, St. Louis, Missouri 63121 Received March 4, 1985 The peroxymonosulfate-acetone system produces dimethyldioxirane under conditions permitting distillation of the dioxirane from the synthesis vessel. The same conditions were used to prepare other methyldioxiranes. Solutions of dimethyldioxirane prepared in this manner were used to study ita chemical and spectroscopic properties. The caroate-acetone system was also used to study the chemistry of in situ generated dimethyldioxirane. Introduction In two cases. lb and IC. it has been re~orted~ Dioxiranes (1) members of the smallest cyclic peroxide that dioxiranes have been isolated and characterized by system, are isomeric with carbonyl oxides 2, one of the physical and chemical methods. In these cases the diox- iranes were synthesized by oxidation of the corresponding 0-0 dilithioalkoxides. 0-0 Dioxiranes have been postulated as intermediates in R &OR I RA R8 reactions involving peracids."l0 Edwards, Curci, and la, R=R'=H 2 lb. R=R'=CF? (1) Lovas, F. J.; Suenram, R. D. Chem. Phys. Lett. 1977,51,453-456. IC, R.CF3, R sCF2CI (2) Martinez, R. I.; Huie, R. E.; Herron, J. T. Chem. Phys. Lett. 1977, Id. R= R'i CH 51,457-459. le, R= CH3, J=CH3CH2 (3) Suenram, R. D.;Lovas, F. J. J. Am. Chem. SOC.1978, 100, lf, R* CH3, R'SCH~CHZCHZ 5117-5122. 10, R. CH3, R' * CH3CH2CH2CH2 (4) Talbott, R. I., Thompson, P. G. U.S. Patent 3632606, 1972. lh, R*R'=CH3CH2 (5) Edwards, J. 0.;Pater, R. H.; Curci, R.; DiFuria, F. Photochem. Photobid.~ .. .. ----.1979. 30.--, 63-70.-- --- peroxidic intermediates involved in the ozonolysis process. (6) Montgomery, R. E. J. Am. Chem. SOC.1974, 96, 7820-7821. (7) Gallopo, A. R.; Edwards, J. 0. J. Org. Chem. 1981,46,1684-1688. Dioxirane la, produced via ozonolysis of ethylene, has been (8)Cicala, G.; Curci, R.; Fiorentino, M.; Laricciuta, 0. J. Org. Chem. characterized by both mass spectral and microwave 1982,47, 267!32673. 0022-3263/85/1950-2847$01.50/0 0 1985 American Chemical Society 2848 J. Org. Chem., Vol. 50, No. 16, 1985 Murray and Jeyaraman co-workersH used the peroxymonosulfate-acetone system Scheme I for stereospecific epoxidation of alkenes. Furthermore Edwards and Curci used a combination of kinetic, ste- reochemical, and ls0-labeling data to suggest that this system produced the dioxirane intermediate Id, which they felt was responsible for the oxygen atom transfer process. A second possible peracid source of a dioxirane was de- scribed by uslh and involves the use of peracetic acid and acetone. We recently reportedlobthe use of the peroxymono- sulfate-acetone system for the conversion of arenes to arene oxides as an extension of the reactions of di- methyldioxirane produced in situ5-l0 and in connection with our studies on the chemistry of carbonyl oxides and the isomeric dioxiranes.'O-l8 The full experimental details of the production of arene oxides and other reactions of dimethyldioxirane in situ are given here along with a de- scription of a modification to the procedure which permits isolation of solutions of the volatile dioxiranes. The so- lutions can be used to study the chemical and spectroscopic 10 properties of the dioxiranes. For example, we have shown that the use of dimethyldioxirane produced in this manner provides an efficient method of epoxide synthesis which is not only stereospecific and results in high yield^^-^ but is unencumbered by the presence of acid, base, high-boiling solvents, and other drawbacks of some of the commonly used epoxidation methods. Results and Discussion U Reactions of in Situ Generated Dimethyldioxirane. Thus we confirm the earlier observations of Edwards and As part of an on-going program designed to distinguish, CurcP that the use of in situ generated dimethyldioxirane if possible, the chemistries of carbonyl oxides and the provides an excellent synthetic method for epoxides.
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