ChemInform Abstract: Reactions of Unsaturated Compounds with the System 1,3,2,4,5‐Dioxadithiazine 2,2,4,4‐Tetroxide‐Base.

Abstract

ChemInform Abstract On treatment with a base, the tetroxide (I) generates 1,2-and/or 1,4-dipolar fragments, which are trapped by the alkenes (II) or by the alkynes (V) to afford products of (2 + 2) cycloaddition, the 1,2-thiazetidine 1,1-dioxides (III) and/or products of (2 + 4) cycloaddition, the 1,4,5-oxathiazine 4,4-dioxides (IV) or (VI). The mechanisms of these cycloadditions are discussed in detail. The derivatives (IIIa) and (IVa) are additionally characterized by X-ray analyses. Compound (IIIa) has the space group P1 with Z=2 and compound (IVa) has the space group P21/b with Z=4. Features of the structures of these compounds are described in detail.

4,6-Disubstituted 1,2,3,5-oxathiadiazine-2,2-dioxides. Synthesis, structural features, chemical properties (Review)

“…R &o I I or llI It has been established [9,12,19,20,23] that formation of compound III in the nitrile-SO 3 system is a reaction which is general and typical of nitriles. Heterocycles III axe obtained from aromatic, alicyalic (including unsaturated), and also halogen-substituted nitriles [9,17,19,20,24]. The molecular structure of three typical representatives of tetroxides III CR = C6H5, n-NO2C6H 4, CC13) has been proven by x-ray diffxaction [19].…”

“…The cyclic adducts III react easily with nitriles and other nucleophilically active compounds [14,16,[21][22][23]. These reactions, depending on the electronic properties of the substituents R, occur in two directions: reactions in which thr C-O bond in the ring of III is broken, and reactions with retention of the indicated bond.…”

“…It has been shown that heterocycles III having donor substituents form 1,2,3,5-oxathiadiazine-2,2-dioxides I with the corresponding nitriles, while tetroxides HI having strong acceptor substituents yield dioxides II with nitriles [16,18,20,26].…”