Annelation of 1,2-cyclononadiene with tetrachlorothiophene dioxide. An ene reaction with sulfur dioxide

Abstract

CH3O-+ CD3CN ^CH3OD + CD2CN-and subsequent exchange. Water can become strongly polarized, especially when occurring in small concentrations in aprotic solvents. This fact may be used to pump aqueous systems via a membrane together with a flow system.The molecules investigated here (Chart I) are models for those of biochemical interest, such as sugars, nucleic acids, etc.There CINOE might well be quite selective. Especially attractive seems the possibility of pumping 15N, where electronic pumps are inefficient because of the negative magnetic moment of l5N and the associated negative enhancement, which causes an initial signal loss. CINOE could provide a superior alternative for positive l5N signal enhancement. The above proton results seem encouraging. References and Notes(1) NATOAdv. Study Inst. Chem. Induced Magn. Polar., Ser. C34, 1977Ser. C34, , 1977 and references therein.(2) Intramolecular CINOE has been reported by: (a) Gloss, G. L; Czeropski,

SO2 Uptake on Oleic Acid: A New Formation Pathway of Organosulfur Compounds in the Atmosphere

“…Sulfur dioxide can react with alkenes via ene-reactions that generally lead to isomerization of the double bond and in some cases to sulfinic acids or polymeric products. − Sulfur dioxide can form π complexes with carbon–carbon double bonds; in some cases (first step of the ene-reaction), the complex may undergo a transformation to the corresponding dipolar σ complex (with charge separation) . Under our conditions (nonpolar surface), radical, rather than ionic reactions might be promoted, leading to diradical intermediates (Figure ).…”

New Organic Chemistry of Sulfur Dioxide

“…Double-bond migration in alkenes 16 can be induced by SO 2 (Scheme ). The process is explained by an ene reaction 16 + SO 2 → 17 followed by a [1,3]-sigmatropic shift 17 → 18 and subsequent retro-ene reaction that gives SO 2 and the isomeric alkenes 19 . – …”

Desulfinylation of Prop-2-enesulfinic Acid: Experimental Results and Mechanistic Theoretical Analysis

“…Products of ene-reaction have been reported for SO 2 reacting with allenes giving the corresponding 1,3-butadiene-2-sulfinic acids (exothermicity of ca. −14 kcal/mol is estimated in this case) and for SO 2 reacting with 6-alkylidenecyclohexa-1,3-diene derivatives producing corresponding-1-phenylalkane-1-sulfinic acid (gain in aromaticity). At this stage it is interesting to compare the ene-reaction of SO 2 with other related heteroene-reactions ( N -sulfinylbenzenesulfonamides and N -sulfinyl-nonafluorobutanesulfonamide under go easy ene-reactions with alkenes, see refs − ).…”

“…They are formed as intermediates in the hydrolysis of sulfinamides, ,,− the reduction of β-ketosulfones, and the oxidation of allylic thiols . They have been proposed as intermediates in SO 2 -mediated alkene isomerization. ,,− As we have shown, this might not always be true . In the case of 1,1-dialkylethenes and trialkyl substituted alkenes, SO 2 generates first polysulfone polymers with the alkenes.…”