I agree Our site saves small pieces of text information (cookies) on your device in order to deliver better content and for statistical purposes. You can disable the usage of cookies by changing the settings of your browser. By browsing our website without changing the browser settings you grant us permission to store that information on your device.
1,3-Dithiane is used in umpolung reactions such as the Corey-Seebach reaction. It acts as a reagent for the deoxygenation of sulfoxides to their corresponding sulfides. Further, it is used as a protecting group for carbonyl compounds used in organic synthesis. It serves as a useful labeled synthon. In addition to this, it is used in the preparation of 2-ethyl-[1,3]dithiane.
The 2-lithio derivative, normally generated with n-BuLi, behaves as a formyl anion equivalent. It has been shown that the rigorous exclusion of atmospheric oxygen minimizes side reactions and is critical in obtaining optimum results in these lithiation procedures: J. Org. Chem., 60, 4258 (1995).
Monoalkylation of the 2-lithio-derivative and cleavage of the dithiane leads to an aldehyde. Successive dialkylation provides a route to ketones. For reviews of the reversal of the normal reactivity of groups, "umpolung", see: Angew. Chem. Int. Ed., 18, 239 (1979), and of the umpolung of carbonyl activity through sulfur-containing reagents: Synthesis, 357 (1977). See also 1,3-Propanedithiol, A15261, 1,3-Dithiolane, L11914, and 1,2-Ethanedithiol, L12865.
For an example of successive acylation and alkylation of 1,3-dithiane, which can be carried out as a one-pot sequence, see: Synthesis, 625 (1980).
Reaction with 2-cyclohexenone proceeds via 1,2-addition. For details of this and subsequent cleavage and rearrangement, see: Org. Synth. Coll., 8, 309 (1993):
Cleavage of 1,3-dithianes has been effected by a variety of methods, including:
Chloramine-T: Synth. Commun., 2, 7 (1972); NCS, AgNO3, acetonitrile-water: J. Org. Chem., 36, 3553 (1971); 48, 1552 (1983); SO2Cl2, silica, DCM-water: Synthesis, 678 (1976); Bromodimethylsulfonium bromide (from DMSO and bromine): Synthesis, 720 (1979); DMSO-HCl-dioxane: Synthesis, 679 (1982); CuCl2, CuO, acetone: Org. Synth. Coll., 6, 109 (1988); CAN, acetonitrile-water: Synth. Commun., 11, 423 (1981); DDQ, acetonitrile-water: J. Chem. Soc., Perkin 1, 453 (1996); Phenyl phosphorodichloridate, NaI, acetonitrile-DMF: Tetrahedron Lett., 29, 5471 (1988); Glyoxylic acid in AcOH: Synthesis, 694 (1976); HIO4, THF-ether: Tetrahedron Lett., 37, 4331 (1996); PhI(OAc)2, acetone-water: Syn. Commun., 30, 4081 (2000). For facilitation of cleavage of 1,3-dithianes by S-alkylation, see Trimethyloxonium tetrafluoroborate, A15175.
For conversion to the dithienium salt by hydride abstraction, see Triphenylcarbenium tetrafluoroborate, A12949.
Reviews: Synthetic uses of 1,3-dithianes: Tetrahedron, 45, 7643 (1989); Chemistry of 1,3-dithioacetals: Organosulfur Chemistry, P. Page, Ed., Academic Press N.Y. (1995).
Unoh, Y.; Hirano, K.; Satoh, T.; Miura, M. Rhodium(III)-Catalyzed Oxidative Alkenylation of 1,3-Dithiane-Protected Arenecarbaldehydes via Regioselective C-H Bond Cleavage. Org. Lett. 2015, 17 (3), 704-707.
Oksdath-Mansilla, G.; Hajj, V.; Andrada, D. M.; Argu?ello, J. E.; Bonin, J.; Robert, M.; Peñéñory, A. B. Photoremoval of Protecting Groups: Mechanistic Aspects of 1,3-Dithiane Conversion to a Carbonyl Group. J. Org. Chem. 2015, 80 (5), 2733-2739.