3-乙酰基-2,3-二氢色烯-4-one

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: Solid 3-acetyl-4-chromanone (0.570 g, 3 mmoles, described in Example 5) is added in portions at room temperature to a suspension of 57% sodium hydride (0.379 g, 9 mmoles) in dry tetrahydrofuran (10 ml). The mixture is heated within 15 min to 60° C and diethyl oxalate (0.438 g, 3 mmoles) in tetrahydrofuran (10 ml) is added. After heating at reflux temperature under an atmosphere of nitrogen for 17 hr., the solvent is removed under reduced pressure, the residue is dissolved in ice-water and extracted with ether. The aqueous phase is acidified with 6N hydrochloric acid and extracted with chloroform. The organic phase is dried, evaporated, and the residue crystallized from methanol-chloroform to give 4-(4-chromanone-3-yl)-2,4-dioxobutyric acid (Vl; R1, R2, R3, Rl4 and R5 = H, and X = O), νmaxnujol 1705, 1615 and 1560 cm-1. is added After heating at reflux temperature under an atmosphere of nitrogen for 17 hr , the solvent is removed under reduced pressure the residue is dissolved in ice-water extracted with ether extracted with chloroform The organic phase is dried evaporated the residue crystallized from methanol-chloroform

反应条件: temp:-40.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: A solution of 3-acetyl-4-chromanone (1.8 g, 9.5 mmoles, described in Example 5) in dry tetrahydrofuran (20 ml) is added dropwise to a suspension of 57% sodium hydride (1.17 g, 28.5 mmoles) in tetrahydrofuran (30 ml) and the mixture is heated at reflux temperature for 15 min. A solution of diethyl oxalate (1.39 g, 9.5 mmoles) is added dropwise under an atmosphere of nitrogen. The reaction mixture is heated at reflux temperature overnight and cooled to -40° C. A solution of 50% aqueous acetic acid (4 ml) is added and the reaction mixture evaporated. The residue is partitioned between chloroform and water, the organic phase is separated and the aqueous phase is re-extracted with chloroform. The combined chloroform extracts are dried and evaporated. The residue is subjected to chromatography on silica gel. Elution with chloroform affords 4-(4-chromanon-3-yl)-2,4-dioxobutyric acid ethyl ester (VII; R1, R2, R3R4 and R17 = H, R19 = C2H5 and X = O), which is crystallized from ether, m.p. 117°-119° C. the mixture is heated at reflux temperature for 15 min The reaction mixture is heated at reflux temperature overnight the reaction mixture evaporated The residue is partitioned between chloroform and water the organic phase is separated the aqueous phase is re-extracted with chloroform The combined chloroform extracts are dried evaporated Elution with chloroform

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: A solution of 3-acetyl-4-chromanone boron difluoride complex (13 g, 54.5 mmoles, described in Example 4) and anhydrous sodium acetate (52 g) in glacial acetic acid (235 ml) is heated on a steam bath for one hr. The solution is poured on ice and the resulting mixture is extracted with ether. The organic extract is washed with aqueous sodium bicarbonate solution and saturated sodium chloride solution, dried and evaporated. The residue is subjected to chromatography on silica gel using benzene-hexane (1:1) as eluant. Evaporation of the eluate gives the title compound, m.p. 73°-74° C, νmaxCHCl 3 1600 cm-1. The solution is poured on ice the resulting mixture is extracted with ether The organic extract is washed with aqueous sodium bicarbonate solution and saturated sodium chloride solution dried evaporated Evaporation of the eluate

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: A solution of 3-acetyl-4-chromanone boron difluoride complex (13 g, 54.5 mmoles, described in Example 4) and anhydrous sodium acetate (52 g) in glacial acetic acid (235 ml) is heated on a steam bath for one hr. The solution is poured on ice and the resulting mixture is extracted with ether. The organic extract is washed with aqueous sodium bicarbonate solution and saturated sodium chloride solution, dried and evaporated. The residue is subjected to chromatography on silica gel using benzene-hexane (1:1) as eluant. Evaporation of the eluate gives the title compound, m.p. 73°-74° C, νmaxCHCl 3 1600 cm-1. The solution is poured on ice the resulting mixture is extracted with ether The organic extract is washed with aqueous sodium bicarbonate solution and saturated sodium chloride solution dried evaporated Evaporation of the eluate

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: A solution of 3-acetyl-4-chromanone boron difluoride complex (13 g, 54.5 mmoles, described in Example 4) and anhydrous sodium acetate (52 g) in glacial acetic acid (235 ml) is heated on a steam bath for one hr. The solution is poured on ice and the resulting mixture is extracted with ether. The organic extract is washed with aqueous sodium bicarbonate solution and saturated sodium chloride solution, dried and evaporated. The residue is subjected to chromatography on silica gel using benzene-hexane (1:1) as eluant. Evaporation of the eluate gives the title compound, m.p. 73°-74° C, νmaxCHCl 3 1600 cm-1. The solution is poured on ice the resulting mixture is extracted with ether The organic extract is washed with aqueous sodium bicarbonate solution and saturated sodium chloride solution dried evaporated Evaporation of the eluate

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: A solution of 3-acetyl-4-chromanone (1.8 g, 9.5 mmoles, described in Example 5) in dry tetrahydrofuran (20 ml) is added dropwise to a suspension of 57% sodium hydride (1.17 g, 28.5 mmoles) in tetrahydrofuran (30 ml) and the mixture is heated at reflux temperature for 15 min. A solution of diethyl oxalate (1.39 g, 9.5 mmoles) is added dropwise under an atmosphere of nitrogen. The reaction mixture is heated at reflux temperature overnight and cooled to -40° C. A solution of 50% aqueous acetic acid (4 ml) is added and the reaction mixture evaporated. The residue is partitioned between chloroform and water, the organic phase is separated and the aqeuous phase is re-extracted with chloroform. The combined chloroform extracts are dried and evaporated. The residue is subjected to chromatography on silica gel. Elution with chloroform affords 4-(4-chromanon-3-yl)-2,4-dioxobutyric acid ethyl ester (VII; R1, R2, R3R4 and R17 = H, R19 = C2H5 and X = 0), which is crystallized from ether, m.p. 117°-119° C. b. Solid 3-acetyl-4-chromanone (0.570 g, 3 mmoles, described in Example 5) is added in portions at room temperature to a suspension of 57% sodium hydride (0.379 g, 9 mmoles) in dry tetrahydrofuran (10 ml). The mixture is heated within 15 min to 60° C and diethyl oxalate (0.438 g, 3 mmoles) in tetrahydrofuran (10 ml) is added. After heating at reflux temperature under an atmosphere of nitrogen for 17 hr., the solvent is removed under reduced pressure, the residue is dissolved in ice-water and extracted with ether. The aqeuous phase is acidified with 6N hydrochloric acid and extracted with chloroform. The organic phase is dried, evaporated, and the residue crystallized from methanol-chloroform to give 4-(4-chromanone-3-yl)-2,4-dioxobutyric acid (VI; R1, R2, R3, R4 and R5 = H, and X = 0), νmaxnujol 1705, 1615 and 1560 cm-1. c. A solution of 4-(4-chromanone-3-yl)-2,4-dioxobutyric acid ethyl ester [0.70 g, 2.4 mmoles, described above in (a)] in methanol is saturated with hydrogen chloride gas. The solution is heated at reflux temperature overnight and evaporated to dryness. The residue is chromatographed on silica gel using benzene-ethyl acetate (4:1). The eluate is evaporated and the residue is crystallized from chloroform-ether to give the title compound, m.p. 173°-174° C. d. In the same manner as described above in (c) but replacing 4(4-chromanone-3-yl)-2,4-dioxobutyric acid ethyl ester with an equivalent amount of the corresponding acid, 4-(4-chromanone-3-yl)-2,4-dioxobutric acid [described above in (b)], the title compound is obtained. R1, R2, R3R4 and R17 = H, R19 = C2H5 and X = 0), which is crystallized from ether, m.p. 117°-119° C. b is added After heating at reflux temperature under an atmosphere of nitrogen for 17 hr , the solvent is removed under reduced pressure the residue is dissolved in ice-water extracted with ether extracted with chloroform The organic phase is dried evaporated the residue crystallized from methanol-chloroform

反应条件: temp:-40.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: A solution of 3-acetyl-4-chromanone (1.8 g, 9.5 mmoles, described in Example 5) in dry tetrahydrofuran (20 ml) is added dropwise to a suspension of 57% sodium hydride (1.17 g, 28.5 mmoles) in tetrahydrofuran (30 ml) and the mixture is heated at reflux temperature for 15 min. A solution of diethyl oxalate (1.39 g, 9.5 mmoles) is added dropwise under an atmosphere of nitrogen. The reaction mixture is heated at reflux temperature overnight and cooled to -40° C. A solution of 50% aqueous acetic acid (4 ml) is added and the reaction mixture evaporated. The residue is partitioned between chloroform and water, the organic phase is separated and the aqeuous phase is re-extracted with chloroform. The combined chloroform extracts are dried and evaporated. The residue is subjected to chromatography on silica gel. Elution with chloroform affords 4-(4-chromanon-3-yl)-2,4-dioxobutyric acid ethyl ester (VII; R1, R2, R3R4 and R17 = H, R19 = C2H5 and X = 0), which is crystallized from ether, m.p. 117°-119° C. b. Solid 3-acetyl-4-chromanone (0.570 g, 3 mmoles, described in Example 5) is added in portions at room temperature to a suspension of 57% sodium hydride (0.379 g, 9 mmoles) in dry tetrahydrofuran (10 ml). The mixture is heated within 15 min to 60° C and diethyl oxalate (0.438 g, 3 mmoles) in tetrahydrofuran (10 ml) is added. After heating at reflux temperature under an atmosphere of nitrogen for 17 hr., the solvent is removed under reduced pressure, the residue is dissolved in ice-water and extracted with ether. The aqeuous phase is acidified with 6N hydrochloric acid and extracted with chloroform. The organic phase is dried, evaporated, and the residue crystallized from methanol-chloroform to give 4-(4-chromanone-3-yl)-2,4-dioxobutyric acid (VI; R1, R2, R3, R4 and R5 = H, and X = 0), νmaxnujol 1705, 1615 and 1560 cm-1. c. A solution of 4-(4-chromanone-3-yl)-2,4-dioxobutyric acid ethyl ester [0.70 g, 2.4 mmoles, described above in (a)] in methanol is saturated with hydrogen chloride gas. The solution is heated at reflux temperature overnight and evaporated to dryness. The residue is chromatographed on silica gel using benzene-ethyl acetate (4:1). The eluate is evaporated and the residue is crystallized from chloroform-ether to give the title compound, m.p. 173°-174° C. d. In the same manner as described above in (c) but replacing 4(4-chromanone-3-yl)-2,4-dioxobutyric acid ethyl ester with an equivalent amount of the corresponding acid, 4-(4-chromanone-3-yl)-2,4-dioxobutric acid [described above in (b)], the title compound is obtained. the mixture is heated at reflux temperature for 15 min The reaction mixture is heated at reflux temperature overnight the reaction mixture evaporated The residue is partitioned between chloroform and water the organic phase is separated the aqeuous phase is re-extracted with chloroform The combined chloroform extracts are dried evaporated Elution with chloroform

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: A solution of 3-acetyl-4-chromanone boron difluoride complex (13 g, 54.4 mmoles, described in Example 4) and anhydrous sodium acetate (52 g) in glacial acetic acid (235 ml) is heated on a steam bath for 1 hr. The solution is poured on ice and the resulting mixture is extracted with ether. The organic extract is washed with aqueous sodium bicarbonate solution and saturated sodium chloride solution, dried and evaporated. The residue is subjected to chromatography on silica gel using benzene-hexane (1:1) as eluant. Evaporation of the eluate gives the title compound, m.p. 73°-74° C, νmaxCHCl3 1,600 cm-1. The solution is poured on ice the resulting mixture is extracted with ether The organic extract is washed with aqueous sodium bicarbonate solution and saturated sodium chloride solution dried evaporated Evaporation of the eluate