Asymmetric Diels-Alder reactions of γ-alkoxy-α-sulfinylbutenolides
摘要:
The synthesis of the enantiomerically pure 5-ethoxy-3-p-tolylsulfinyl-2(5H)-furanones (2a and 2b) and the study of their behaviour as dienophiles in asymmetric Diels-Alder reactions with cyclopentadiene arc reported. Depending on the reaction conditions, the pi-facial selectivity is mainly controlled by the sulfur or C-5 configurations.
Totally Regio- and Stereoselective Behavior of Mono- and Diactivated Cyclic Alkenes in the Lu Reaction: Synthesis of Enantiopure Functionalized Cyclopentanes
作者:José L. García Ruano、Alberto Núñez, Jr.、M. Rosario Martín、Alberto Fraile
DOI:10.1021/jo801896a
日期:2008.12.5
5-Alkoxyfuran-2(5H)-ones and their optically pure 3-p-tolylsulfinyl derivatives, synthetic equivalents of the acyclic esters, react with dipoles generated from allenoates and PPh(3) (Lu reaction), in a completely regioselective, pi-facial selective and endo-selective manner, yielding bicyclic adducts, which are easily converted into optically pure highly substituted cyclopentane derivatives.
Abnormal Behaviour of Allenylsulfones under Lu’s Reaction Conditions: Synthesis of Enantiopure Polyfunctionalised Cyclopentenes
作者:Alberto Núñez、M. Rosario Martín、Alberto Fraile、José L. García Ruano
DOI:10.1002/chem.200903185
日期:2010.5.10
adducts in good yields. Allenylsulfones evolve through a different mechanism to that proposed for allenoates (Lu’sreaction) and afford bicyclic adducts in which the sulfonyl group is joined to C‐5. This has advantages on the stereochemical control of further reactions leading to enantiomerically pure polyfunctionalisedcyclopentenes and cyclopentanes.
Pyrrolo[2,1-<i>b</i>]thiazole Derivatives by Asymmetric 1,3-Dipolar Reactions of Thiazolium Azomethine Ylides to Activated Vinyl Sulfoxides
作者:José Luis García Ruano、Alberto Fraile、M. Rosario Martín、Gema González、Cristina Fajardo
DOI:10.1021/jo801705d
日期:2008.11.7
1,3-Dipolar reactions of thiazolium azomethine ylides to enantiopure cyclic and acyclic vinyl sulfoxides provide an efficient access to polyfunctionalized pyrrolo[2,1-b][1,3]thiazoles in a highly regio- and stereoselective manner. Regioselectivity can be inverted by modifying the position of the sulfinyl group at the double bond of the sulfinylfuranones. The sulfoxide is the main controller of the
Asymmetric synthesis of 4-ethoxy-1-p-tolylsulfonyl-3,6-dioxabicyclo[3.1.0]hexan-2-ones
作者:Alberto Fraile、José Luis García Ruano、M. Rosario Martín、Amelia Tito
DOI:10.1016/j.tet.2009.10.106
日期:2010.1
epoxidation at the electron deficient double bond by treatment with MCPBA at room temperature to afford, in good yields, enantiomerically pure 4-ethoxy-5-alkyl-1-p-tolylsulfonyl-3,6-dioxabicyclo[3.1.0]hexan-2-ones. These epoxyfuranones are obtained along with cyclopropanefuranones by reaction of 4-ethoxy-6-p-tolylsulfinylfuro[3,4-c]pyrazolin-6-ones with MPCBA. In both cases, the formation of the sulfonyl
(Ss)-5-ethoxy-3-p-tolylsulfinylfuran-2(5H)-ones as chiral dipolarophiles: First asymmetric cycloaddition of diazomethane to vinyl sulfoxides
作者:Jose L. García Ruano、Alberto Fraile、M. Rosario Martín
DOI:10.1016/0957-4166(96)00233-9
日期:1996.7
Cycloadditions of diazomethane to (Ss)-5-ethoxy-3-p-tolylsulfinylfuran-2(5H)-ones 1a–b and their corresponding 4-methyl derivatives 3a–b, proceeds in quantitative yields, to give enantiomerically pure 3H,6H,3a,6a-dihydrofuro[3,4-c]pyrazol-4-ones 2a–b and 4a–b, respectively. The sulfinyl group at C-3 strongly increases both the reactivity and the π-facial selectivity. The dipole approach mode is determined