17557-41-4Relevant academic research and scientific papers
A CONVENIENT METHOD FOR HETEROLYTIC CHLORINATION WITH SULFURYL CHLORIDE AND CATALYSTS FOR THE GENERATION AND RECYCLING OF CHLORINE
Buyck, Laurent De,Accou, Peter
, p. 669 - 672 (2007/10/02)
By catalyzed decomposition of hot sulfuryl chloride chlorine is produced in the presence of substrates of relatively low reactivity.A condensor system equipped with a cooled solid catalyst recovers and recycles chlorine otherwise escaping with the waste gas.This principle was successfully applied for the heterolytic selective α,β,β-trichlorination of ethers in the dark.For the equilibrium production of chlorine in hot sulfuryl chloride salts of organic bases were active catalysts at very low concentration, while some cyclic ethers showed autocatalytic activity.Pellets of activated carbon or anion exchanger resin were suitable for a cold catalysis.The recycling improved from about 86percent at room temperature to almost quantitative below -10 deg C over reaction periods up to 6 days.
CATALYSED QUANTITATIVE SYNTHESIS OF 2,3,3-TRICHLOROTETRAHYDROFURAN
Buyck, Laurent de,Lepeleire, Carine de
, p. 553 - 558 (2007/10/02)
Tetrahydrofuran was chlorinated in the presence of N,N-dimethyloctylamine (1 mmol per mol optimal) with an excess of sulfuryl chloride at 55-80 deg C.After a first stage producing trans 2,3-trichloro THF (1) the reaction proceeded to complete conversion to 2,3,3-trichloro THF (2) in less than 22 h. The mechanism is discussed in terms of an inhibitory effect of hydrogen chloride and a catalytic role for anions unintentionally derived from the sulfuryl chloride. Equilibration of 2 with the isomer 2,2,4-trichlorobutanal (3) was observed at 130-170 deg C with hydrogen chloride catalysis, at 70 deg C with titanium tetrachloride or zinc chloride.
β-Halogeno Ether Synthesis of Olefinic Alcohols: Stereochemistry and Conformation of 2-Substituted 3-Halogenotetrahydro-pyran and furan Precursors
Crombie, Leslie,Wyvill, Robert D.
, p. 1971 - 1982 (2007/10/02)
Ring-scission of cis- or trans-2-alkyl- (or aryl-) 3-chlorotetrahydropyrans proceeds regioselectively and highly stereoselectively to give (E)-alk-4-en-1-ols, but in the parallel tetrahydrofuran series (Z)-/(E)-mixtures, dependent on percursor geometry, are formed.In this paper the stereochemistry and conformation of the tetrahydro-pyran and - furan precursors are considered.The cis/trans-composition of 2,3-dihalogenotetrahydro-pyrans and-furans made by various routes is reported.Reaction with Grignard reagents gives separable cis-/trans-mixtures the stereoisomeric composition of which, in the cases examined, does not depend on the stereoisomeric composition of the dihalide, but does vary with the halogen and the composition of the Grignard or dialkylmagnesium; possible reasons are discussed.The stereochemistry and conformation of the 2-alkyl- (or aryl-)3-chlorotetrahydropyrans is analysed by n.m.r. methods (J2a,3acis ca. 1.5 Hz; J2a,3atrans ca. 9.8 Hz) but assignments for the two tetrahydrofuran series with J2,3 2.6-3.6 and 4.3-5.9 are made uncertain by pseudorotation.The stereochemical identity of the two series is rigorously proved by isolation of cis- and trans-2-allyl-3-chlorotetrahydrofuran.On the one hand the former is hydrogenated to the cis-2-propyl compound, correlated with other members of the alkyl series, but on the other it is oxidised and the acid is converted into the cis-p-bromophenyl ester.The stereochemistry and conformation of the latter is rigorously demonstrated by an X-ray structure.The stereochemistries and conformations of the 2-deuterio- and 2-methoxy-3-chlorotetrahydropyrans are discussed, and consideration is then extended to the 2-alkyl-3-chloro-2-methyltetrahydro-pyran and -furan series.
