Tetrahydrothiophene 1,1-Dioxide Derivatives

Faith, H. Eldridge; Kautsky, Marie P.; Abreu, Benedict E.

doi:10.1021/jo01055a040

Cited by 10 publications

(2 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A mixture of sulfolene 11f (150 mg, 0.09 mmol), MeOH (3 mL), and 10% Pd/C (20 mg) was degassed on the vacuum line and pressurized with H 2 (30 bar). After shaking at 25 °C for 12 h, the catalyst was filtered off, the solvent evaporated, and the residue purified by flash chromatography on silica gel (CH 2 Cl 2 ) giving 40 mg (25%) of yellowish oil identical (spectral data) with the 2-bromosulfolane prepared according to Faith et al…”

Section: Methodsmentioning

confidence: 99%

Competition between Hetero-Diels−Alder and Cheletropic Addition of Sulfur Dioxide. Theoretical and Experimental Substituent Effects on the Relative Stability of 3,6-Dihydro-1,2-oxathiin-2-oxides (Sultines) and 2,5-Dihydrothiophene-1,1-dioxides (Sulfolenes). Anomeric Effects in Sultine and 6-Substituted Derivatives

et al. 1998

View full text Add to dashboard Cite

At low temperature and in the presence of CF 3 COOH, SO 2 undergoes Diels-Alder additions with (E)-1-acetoxybutadiene (8d) giving a 1:10 mixture of diastereomeric 6-acetoxysultines (9d + 10d). The Van't Hoff plot for equilibria 8d + SO 2 a 9d + 10d led to ∆H r ) -7.0 ( 0.3 kcal/mol, ∆S r ) -42 ( 3 cal‚mol -1 ‚K -1 . At 20 °C, 8d underwent a slow cheletropic addition with SO 2 giving 2-acetoxysulfolene (11d, ∆H r = -11.5 kcal/mol), the structure of which was established by singlecrystal X-ray diffraction studies. (E)-Chloro (8e) and (E)-bromobutadiene (8f) did not undergo Diels-Alder additions with SO 2 , even in the presence of protic or Lewis acid promoters. Low yields of 2-chloro-(11e) and 2-bromosulfolene (11f) were obtained at 20 °C. The structure of 11e was confirmed by single-crystal X-ray diffraction. The potential energy hypersurfaces of the Diels-Alder and cheletropic additions of SO 2 to butadiene (8a), (E)-piperilene (8b), (E)-1-methoxy-(8c), (E)-1-acetoxy-(8d), and (E)-1-chlorobutadiene (8e) were studied by ab initio quantum calculations at the MP2/6-31G* level. In agreement with the experiment, 6-substituted sultines 9X and 10X were less stable than the corresponding 2-substituted sulfolenes 11X for X ) Me, OAc, Cl. With X ) OMe, the two diastereomeric 6-methoxysultines (9c, 10c) and 2-methoxysulfolene (11c) were calculated to have similar stabilities. This is attributed to a stabilizing thermodynamic anomeric effect or gem-sulfinate/methoxy disubstitution effect in 9c, 10c. Such effects were not detected for sulfinate/acetoxy (9d, 10d) and sulfinate/chloro (9e, 10e) disubstitutions. The relative instability of 2-acetoxy-(11d) and 2-chlorosulfolene (11e) compared with their cycloaddents is attributed to repulsive interactions between the SO 2 moieties and the 2-substituents. The Alder endo mode of [4 + 2] cycloaddition of SO 2 is predicted to be faster than the "anti-Alder mode" of additions for dienes 8X, X ) Me, OMe, OAc, Cl. The resulting diastereomeric sultines 9X and 10X, respectively, exist as equilibria (energy barrier: ca. 5-6 kcal/mol) of two conformers 9X a 9′X, 10X a 10′X. In general, the conformers 9X, 10X with pseudoaxial SdO group are preferred (conformational anomeric effect of the sulfinate moiety). Repulsive interactions between pseudoaxial SdO and polar cis-6substituents (e.g.: X ) OMe, OAc) in 9X may render conformers 9′X (with the SdO and 6-X groups in pseudoequatorial positions) as stable as conformers 9X. The calculations predict the existence of conformational anomeric effects of 2-3 kcal/mol for the gem-sulfinate/methoxy (9c, 10′c) and gem-sulfinate/acetoxy disubstitution (9d, 10′d).

show abstract

Section: Methodsmentioning

confidence: 99%

Competition between Hetero-Diels−Alder and Cheletropic Addition of Sulfur Dioxide. Theoretical and Experimental Substituent Effects on the Relative Stability of 3,6-Dihydro-1,2-oxathiin-2-oxides (Sultines) and 2,5-Dihydrothiophene-1,1-dioxides (Sulfolenes). Anomeric Effects in Sultine and 6-Substituted Derivatives

et al. 1998

View full text Add to dashboard Cite

show abstract

“…Dedicated to Professor Yu-SMaCheng on the occasion of her 65th birthday. BzO""""""'" 11 INNaOH more forcing condition (IN NaOH) failed to cause the formation of either 18 or 19. Instead, compound 20 was produced in 51% yield.…”

mentioning

confidence: 99%

A Cyclization Approach toward Five‐Membered Heteroaromatico‐QuinodimethanesviaFused‐3‐Sulfolenes

Chou

Tsai

Lee

1997

J Chinese Chemical Soc

View full text Add to dashboard Cite

A general strategy involving the zineation of 4-bromo-3-chloro-2-sulfolene, in situ condensation with an rr-heterosubstituted acetaldehyde, and subsequent cyclization reaction as the key steps toward the synthesis of furano-and thieno-Svsulfolenes is described. These fused-S-sulfolenes are demonstrated to be good precursors for the corresponding o-quinodimethanes.The synthetic plan for furano-f-sulfolene 4 involved thc reaction of a three-atom unit 10 with a latent form of the 8 Scheme I 4

show abstract

Verbesserte Synthese von 2,6‐Dicyan‐1,5‐dimethylsemibullvalen aus 1,5‐Dimethylbicyclo[3.3.0]octan‐3,7‐dion

Quast¹,

Mayer²

1988

Liebigs Ann. Chem.

View full text Add to dashboard Cite

Das 3,7-Diketon 6 reagiert mit Thiophenolen in Gegenwart von Titan(IV)-chlorid/Triethylamin zu gleichen Mengen der Bis(vinylsulfide) C2/C.,-13 (Ausb. 87-93%), die-unter TrifluoressigGure-Katalyse zu einem (3: 1)-Gemisch aquilibriert werden. Oxidation von C2/ca-13 mit Natriumperborat-tetrahydrat in Essigsaure ergibt fast quantitativ die Bis(viny1sulfone) The 3,7-dike'tone 6 reacts with thiophenols in the presence of titanium tetrachloride/triethylamine affording equal amounts of the vinyl sulfides Cz/C,-13 in 87-93% yield. Equilibration of the 1 : 1 mixture of C2/C,-13 is catalyzed by trifluoroacetic acid and produces a 3: 1 ratio of C-,-and C,-13. Sodium perborate tetrahydrzte in acetic acid oxidizes the vinyl sulfides C2/Cv-13 to the vinyl sulfones C2/C,-14 in almost quantitative yield. Potassium cyanide supported on aluminium oxide in boiling 2-methyl-2-butanol converts the latter into a mixture of the a$-unsaturated Diketon 6 fuhrte auch zum 2,6-Diketon 7 aber nur in sieben Schritten mit bescheidener Ausbeute').3,7-Diketone vom Typ 6 rnit einer breiten Auswahl von Substituenten an den Bruckenkopf-Kohlenstoffatomen erhalt man sehr bequem durch Weiss-Reaktion von 1,2-Dicarbonylverbindungen rnit 3-O~oglutarsaure-dimethylester'~) und anschlieBende Hydrolyse sowie Decarboxylierung. Bevor man aber Substituenten an C-2 und C-6 nucleophil einfuhren kann, zum Beispiel Nitrilgruppen als Cyanid, um zum 2,6-Dinitril8 zu gelangen, muR das 3,7-Diketon 6 umgepolt werden. Statt das durch 1,2-Carbonylverschiebung zu erreichen'), kann man 6 in eine Vinylverbindung mit Elektronen-

show abstract

Tetrahydrothiophene 1,1-Dioxide Derivatives

Cited by 10 publications

References 0 publications

A Cyclization Approach toward Five‐Membered Heteroaromatico‐QuinodimethanesviaFused‐3‐Sulfolenes

Verbesserte Synthese von 2,6‐Dicyan‐1,5‐dimethylsemibullvalen aus 1,5‐Dimethylbicyclo[3.3.0]octan‐3,7‐dion

Contact Info

Product

Resources

About