Heterocyclic fused 2,5-dihydrothiophene S,S-dioxides as precursors to heterocyclic o-quinodimethanes
作者:Lynne M. Chaloner、Andrew P.A. Crew、Paul M. O'Neill、Richard C. Storr、Michael Yelland
DOI:10.1016/s0040-4020(01)80480-4
日期:1992.1
5-bischloromethylthiophene-2-carboxylate by reaction with sodium sulfide and oxidation. Pyrazole fused analogues 15 and 16 (R = Me and COPh) were prepared from 3-phenylsulfonyl-2,5-dihydrothiophene S,S-dioxide by cycloaddition of diazomethane, base induced aromatisation and N-substitution of the sulfone 14. Reaction of 3-acetyl-4-phenylthio-2,5-dihydrothiophene S,S-dioxide with hydrazine and interception of
2,5-Dihydrothiophene 5,5-dioxides 8 and 6 have been obtained by interception of flash-pyrolytically produced 2,3-dihydro-2,3-bis(methylene)thiophene with sulfur dioxide and from methyl 4,5-bischloromethylthiophene-2-carboxylate by reaction with sodium sulfide and oxidation. Pyrazole fused analogues 15 and 16 (R = Me and COPh) were prepared from 3-phenylsulfonyl-2,5-dihydrothiophene S,S-dioxide by cycloaddition
Formation and [4 + 2] cycloaddition reactions of 2,3-dimethylene-2,3-dihydrothiophene
作者:Keimpe J. van den Berg、Albert M. van Leusen
DOI:10.1002/recl.19931120103
日期:——
2,3-Dimethylene-2,3-dihydrothiophene (1), the thiophene analog of o-xylylene (o-quinodimethane), was generated in situ from the (trialkylammoniomethyl)-(trimethylsilylmethyl)thiophene iodides 4 or 5 by fluoride-induced 1,4 climination, and was trapped by [4 + 2] cycloadditions with a series of dienophiles. The reaction of 1 with dimethyl fumarate was considerably faster than with dimethyl maleate.
Facile synthesis of 4,6-dihydrothieno[3,4-b]thiophene 5,5-dioxide. A synthetic equivalent of 2,3-dihydro-2,3-dimethylenethiophene
作者:Ta-Shue Chou、Chung-Ying Tsai
DOI:10.1039/c39910001287
日期:——
4,6-Dihydrothieno[3,4-b]thiophene 5,5-dioxide 4, a stable precursor of 2,3-dihydro-2,3-dimethylenethiophene 3, conveniently prepared from 4-bromo-3-chloro-2,3-dihydrothiophene S,S-dioxide, can easily be alkylated and loses SO2 upon heating so that 4 serves as a useful synthetic equivalent of 3.
4,6-二氢噻吩并[3,4- b ]噻吩-5,5-二氧化物4,2,3-二氢-2,3- dimethylenethiophene的稳定前体3,方便地从4-溴-3-氯-2-制备3-二氢噻吩S(S-二氧化物)很容易被烷基化,加热时失去SO 2,因此4可用作3的有用合成当量。
The generation of 2,3-dihydro-2,3-bis-(methylene)thiophenes from 4,6-dihydrothieno[3,4-b]thiophene 5,5-dioxides
作者:A.P.A. Crew、G. Jenkins、R.C. Storr、M. Yelland
DOI:10.1016/s0040-4039(00)88841-3
日期:1990.1
CREW, A. P. A.;JENKINS, G.;STORR, R. C.;YELLAND, M., TETRAHEDRON LETT., 31,(1990) N0, C. 1491-1494
作者:CREW, A. P. A.、JENKINS, G.、STORR, R. C.、YELLAND, M.