59892-15-8Relevant academic research and scientific papers
Organic Reactions of Sulfur Dioxide. Reactions with Nucleophilic Duoble Bonds Leading to the Isomerization, Aromatization, Selective Hydrogen-Deuterium Exchange, and Electron-Transfer Processes
Masilamani, Divakar,Manahan, Edward H.,Vitrone, John,Rogic, Milorad M.
, p. 4918 - 4931 (2007/10/02)
Sulfur dioxide reacts readily with 1-alkoxycyclohexenes to give unstable 1,2,3,4,5a,6,7,8,9,9b-decahydro-4a,9a-dialkoxydibenzothiophene 5,5-dioxides, which, after elimination of alcohol, afford crystalline 1,2,3,4,5a,6,7,8,9-nonahydro-4a-alkoxydibenzothiophene 5,5-dioxides.These tricyclic sulfones undergo sulfur dioxide extrusion to give a 1:1 mixture of 2- and 6-cyclohex-1-enyl-1-alkoxy-1-cyclohexenes.This mixture of the 1,3- and 1,4-dienes reacts quantitatively with sulfur dioxide to give back the starting tricyclic sulfones.The apparent isomerization of the 1,4-diene to 1,3-isomer is an example of a quite general isomerization of a wide variety of olefins in sulfur dioxide.It appears that these reactions involve the allylic sulfinic acids as transient intermediates, which are capable of a very facile 1,3-thiaallylic rearrangement.When the reactions of those olefins that do undergo isomerization in liquid sulfur dioxide are carried out in the presence of deuterium oxide, a highly stereospecific hydrogen-deuterium exchange is observed.For example, optically active 1-methyl-4-isopropyl-cyclohexene affords 6,6-dideuterio-1-(trideuteroimethyl)-4-isopropylcyclohexene without appreciable racemization. 1,4-Cyclohexadienes react with liquid sulfur dioxide at room temperature to give quantitatively the aromatic hydrocarbon, elemental sulfur, and water. 1,4-Disubstituted 1,3-cyclohexadienes, on the other hand, under similar conditions provide only a small amount of the aromatic hydrocarbon, the main product being a polymeric hydrocarbon(s).Surprisingly, 1-methyl-4-isopropyl-1,3-cyclohexadiene in the presence of oxygen provided 1-methyl-4-isopropylbenzene exclusively.This reaction involves ascaridole as the intermediate, which then reacts with sulfur dioxide to give the aromatic hydrocarbon and sulfuric acid.When the reaction with oxygen is conducted at a low temperature, the ascaridole can be obtained in a quantitative yield.The mechanisms of olefin isomerization, hydrogen-deuterium exchange, and aromatization of cyclohexadienes are discussed.
Sulfuryl Chloride as a Reagent for Selective Chlorination of Symmetrical Ketones and Phenols
Masilamani, Divakar,Rogic, Milorad M.
, p. 4486 - 4489 (2007/10/02)
Cyclohexanone reacts with sulfuryl chloride in sulfur dioxide, ether, tetrahydrofuran, dioxane, and tetraglyme to give mixtures of mono- and dichlorocyclohexanones.However, when the reaction was carried out in sulfur dioxide solution containing a slight excess of methanol, only monochlorocyclohexanone was obtained in high yield.Almost as good selectivities are obtained in methylene chloride solution in the presence of methanol.A similar procedure with acetone affords monochloroacetone cleanly.While phenols do not react with sulfuryl chloride in methylene chloride even under reflux, the chlorination can be induced by the addition of various organic "bases", resulting in selective monochlorination.
