Starting from（5S）-（L-menthyloxy）-3,4-dibromo-5H-furan-2-one and L-leucine,the title compound N-[（2S）-4-bromo-2-（L-menthyloxy）-5-oxo-2,5-dihydro-3-furyl]-L-leucine 5（C20H32BrNO5,Mr = 446.37） was obtained in o...Starting from（5S）-（L-menthyloxy）-3,4-dibromo-5H-furan-2-one and L-leucine,the title compound N-[（2S）-4-bromo-2-（L-menthyloxy）-5-oxo-2,5-dihydro-3-furyl]-L-leucine 5（C20H32BrNO5,Mr = 446.37） was obtained in one-pot process via the tandem Michael addition-elimination reaction in the presence of potassium hydroxide.The chemical structure and absolute configuration of the title compound were confirmed via rotation,UV-Vis,FT-IR,1H NMR,13C NMR,MS and elemental analysis,especially by the X-ray single-crystal diffraction.The crystal crystallizes in an orthorhombic system,space group P212121 with a = 12.5249（16）,b = 19.005（3）,c = 19.719（3） ,V = 4693.7（10） 3,Z = 8,Dc = 1.263 g/m3,μ = 1.778 mm-1,F（000） = 1872,the final R = 0.0617 and wR = 0.1576 for 3967 observed reflections（I 2σ（I））.X-ray analysis reveals that the title compound has two independent molecules in the asymmetric part of the unit cell with the two five-membered furanones being almost planar.The essential part of the electron delocalization is concentrated in the N（1）,C（3）,C（1）,C（37） and O（7） region and N（2）,C（28）,C（27）,C（30） and O（4） region in the other molecule respectively,but does not take place at the expense of delocalization within the ester function.展开更多
The double Michael reactions between benzofuran-3-one or 1-indone and symmetric dienones in the presence of catalytic ionic liquids were successfully developed and spiro[benzofuran-2, 1′-cyclohexane]-3-one or spiro[c...The double Michael reactions between benzofuran-3-one or 1-indone and symmetric dienones in the presence of catalytic ionic liquids were successfully developed and spiro[benzofuran-2, 1′-cyclohexane]-3-one or spiro[cyclo- hexane-1,2′-indene]-1′,4（3′H）-dione derivatives containing a spiro quaternary stereogenic center, which widely exist in biologically active products and building blocks in organic synthesis, were obtained in excellent yields （up to 99%）. This catalytic system was also extended to the double Michael reaction of less reactive 1-indone and the desired products were also obtained in 31%-62% yields. The catalytic system was highly active and efficient for a broad of substrates under mild conditions.展开更多
A convenient and efficient method was developed for the synthesis of 2,2＇-（arylmethylene）bis（3-hydrox- ycyclohex-2-enone） derivatives via the oleylamine-catalyzed tandem Knoevenagel/Michael addition reactions of ...A convenient and efficient method was developed for the synthesis of 2,2＇-（arylmethylene）bis（3-hydrox- ycyclohex-2-enone） derivatives via the oleylamine-catalyzed tandem Knoevenagel/Michael addition reactions of aromatic aldehydes and cyclohexane-1,3-diones. This transformation proceeded without any metal catalyst in non-toxic solvent at room temperature with high isolated yields. A plausible mechanism for this process was pro- posed.展开更多
Tandem asymmetric double Michael addition/internal nucleophilic substitution of the novel chiral source, 5-(l-menthyloxy)-3-bromo-2(5H)-furanone with nucleophilic alcohol compounds has been investigated. The tandem as...Tandem asymmetric double Michael addition/internal nucleophilic substitution of the novel chiral source, 5-(l-menthyloxy)-3-bromo-2(5H)-furanone with nucleophilic alcohol compounds has been investigated. The tandem asymmetric reaction can afford four new stereogenic centers with one reaction and give optically pure spiro-cyclopropane derivatives 5a--5d which are difficult to obtain by routine methods. The synthetic method for 5a--5d was studied in detail and the new compounds were identified on the basis of their analytical data and spectroscopic data, such as [α]^(20),IR,~1H NMR,^(13)C NMR, MS and elementary analysis. The absolute configuration of the sprio [5-l-menthyloxy-3-bromo butyrolactocyclopropane-3″, 3′(4′-methyloxy-5′-menthyloxybutyrolactone)] (5a) was established by X-ray crystallography. The work can provide important synthetic strategy in synthesis of some new optically active spiro-cyclopropane analogues and some biologically active molecules with complex structure.展开更多
In this paper, stereocontrolled tandem Michael addition-elimination reaction of the novel chiral source, S-(ι-menthyloxy)-3,4-dichloro-2(5H)-furanone, with various thiols and amines has been investigated. A series of...In this paper, stereocontrolled tandem Michael addition-elimination reaction of the novel chiral source, S-(ι-menthyloxy)-3,4-dichloro-2(5H)-furanone, with various thiols and amines has been investigated. A series of new enantiomerically pure compounds, 5-(ι-menthyloxy)-4-substituted-3-cnloro-2(5H)-furanones, were obtained in good yields with d. e.(?)98% under mild conditions.展开更多
基金Supported by the National Natural Science Foundation of China (No. 20772035)the Natural Science Foundation of Guangdong Province (No. 5300082)
文摘Starting from（5S）-（L-menthyloxy）-3,4-dibromo-5H-furan-2-one and L-leucine,the title compound N-[（2S）-4-bromo-2-（L-menthyloxy）-5-oxo-2,5-dihydro-3-furyl]-L-leucine 5（C20H32BrNO5,Mr = 446.37） was obtained in one-pot process via the tandem Michael addition-elimination reaction in the presence of potassium hydroxide.The chemical structure and absolute configuration of the title compound were confirmed via rotation,UV-Vis,FT-IR,1H NMR,13C NMR,MS and elemental analysis,especially by the X-ray single-crystal diffraction.The crystal crystallizes in an orthorhombic system,space group P212121 with a = 12.5249（16）,b = 19.005（3）,c = 19.719（3） ,V = 4693.7（10） 3,Z = 8,Dc = 1.263 g/m3,μ = 1.778 mm-1,F（000） = 1872,the final R = 0.0617 and wR = 0.1576 for 3967 observed reflections（I 2σ（I））.X-ray analysis reveals that the title compound has two independent molecules in the asymmetric part of the unit cell with the two five-membered furanones being almost planar.The essential part of the electron delocalization is concentrated in the N（1）,C（3）,C（1）,C（37） and O（7） region and N（2）,C（28）,C（27）,C（30） and O（4） region in the other molecule respectively,but does not take place at the expense of delocalization within the ester function.
文摘The double Michael reactions between benzofuran-3-one or 1-indone and symmetric dienones in the presence of catalytic ionic liquids were successfully developed and spiro[benzofuran-2, 1′-cyclohexane]-3-one or spiro[cyclo- hexane-1,2′-indene]-1′,4（3′H）-dione derivatives containing a spiro quaternary stereogenic center, which widely exist in biologically active products and building blocks in organic synthesis, were obtained in excellent yields （up to 99%）. This catalytic system was also extended to the double Michael reaction of less reactive 1-indone and the desired products were also obtained in 31%-62% yields. The catalytic system was highly active and efficient for a broad of substrates under mild conditions.
基金Supported by the National Natural Science Foundation of China（Nos.21772001, 21372008）, the Natural Science Foundation of Education Administration of Anhui Province, China（No.KJ2016A267）, the Special and Excellent Research Fund of Anhui Normal Universit and the Doctoral Scientific Research Foundation of Anhui Normal University, China（No.2016XJJ110）.
文摘A convenient and efficient method was developed for the synthesis of 2,2＇-（arylmethylene）bis（3-hydrox- ycyclohex-2-enone） derivatives via the oleylamine-catalyzed tandem Knoevenagel/Michael addition reactions of aromatic aldehydes and cyclohexane-1,3-diones. This transformation proceeded without any metal catalyst in non-toxic solvent at room temperature with high isolated yields. A plausible mechanism for this process was pro- posed.
基金Project supported by the National Natural Science Foundation of China (Grant No. 29672004)
文摘Tandem asymmetric double Michael addition/internal nucleophilic substitution of the novel chiral source, 5-(l-menthyloxy)-3-bromo-2(5H)-furanone with nucleophilic alcohol compounds has been investigated. The tandem asymmetric reaction can afford four new stereogenic centers with one reaction and give optically pure spiro-cyclopropane derivatives 5a--5d which are difficult to obtain by routine methods. The synthetic method for 5a--5d was studied in detail and the new compounds were identified on the basis of their analytical data and spectroscopic data, such as [α]^(20),IR,~1H NMR,^(13)C NMR, MS and elementary analysis. The absolute configuration of the sprio [5-l-menthyloxy-3-bromo butyrolactocyclopropane-3″, 3′(4′-methyloxy-5′-menthyloxybutyrolactone)] (5a) was established by X-ray crystallography. The work can provide important synthetic strategy in synthesis of some new optically active spiro-cyclopropane analogues and some biologically active molecules with complex structure.
基金Project (No. 29132036) supported by the National Natural Science Foundation of China
文摘In this paper, stereocontrolled tandem Michael addition-elimination reaction of the novel chiral source, S-(ι-menthyloxy)-3,4-dichloro-2(5H)-furanone, with various thiols and amines has been investigated. A series of new enantiomerically pure compounds, 5-(ι-menthyloxy)-4-substituted-3-cnloro-2(5H)-furanones, were obtained in good yields with d. e.(?)98% under mild conditions.
