In this paper, it was found that isopropylidene (1-hydroxy-3-oxo-butylidene) malonate 4 was a heat unstable compound and the one step convenient methods for preparation of 4-hydroxy-6-methyl-2-pyrone 1 and 3-carboxy-4...In this paper, it was found that isopropylidene (1-hydroxy-3-oxo-butylidene) malonate 4 was a heat unstable compound and the one step convenient methods for preparation of 4-hydroxy-6-methyl-2-pyrone 1 and 3-carboxy-4-hydroxy-6-methyl-2-pyrone 2 in good yields were reported. Isopropylidene malonate 3、diketen and triethylamine reacted in chloroform to give 2, and in the mixture of dichloromethane and chlorobenzene to offer 1.展开更多
3,4Dehydro3hydroxy4phenylpyran2,5dione is an important intermediate of benzoquinones which have the ability to reduce plasma level of glucose.We selected a novel method to prepare the intermediate from...3,4Dehydro3hydroxy4phenylpyran2,5dione is an important intermediate of benzoquinones which have the ability to reduce plasma level of glucose.We selected a novel method to prepare the intermediate from phenylacetyl chloride in this paper.The facile synthetic scheme put forward in this paper is simple to operate and has the characteristic of high yield and good feasibility.展开更多
Aim To study the chemical composition of Opuntia dillenii Haw. Methods Manykinds of chromatogra-phy methods were used in the isolation procedure, while the structures ofisolated compounds were determined on the aids o...Aim To study the chemical composition of Opuntia dillenii Haw. Methods Manykinds of chromatogra-phy methods were used in the isolation procedure, while the structures ofisolated compounds were determined on the aids of NMR and MS spectral analysis. Result Three newcompounds, together with 14 known compounds, were isolated form the 80% ethanolic extract of itsstems. Conclusion The three new compounds, opuntioside Ⅰ (2), 4-ethoxyl-6-hydroxymethyl-α-pyrone(3) and kaempferol 7-O-β-D-glucopyranosyl (1→4)-β-D-glucopyranoside (4), were characterized.展开更多
文摘In this paper, it was found that isopropylidene (1-hydroxy-3-oxo-butylidene) malonate 4 was a heat unstable compound and the one step convenient methods for preparation of 4-hydroxy-6-methyl-2-pyrone 1 and 3-carboxy-4-hydroxy-6-methyl-2-pyrone 2 in good yields were reported. Isopropylidene malonate 3、diketen and triethylamine reacted in chloroform to give 2, and in the mixture of dichloromethane and chlorobenzene to offer 1.
文摘3,4Dehydro3hydroxy4phenylpyran2,5dione is an important intermediate of benzoquinones which have the ability to reduce plasma level of glucose.We selected a novel method to prepare the intermediate from phenylacetyl chloride in this paper.The facile synthetic scheme put forward in this paper is simple to operate and has the characteristic of high yield and good feasibility.
文摘Aim To study the chemical composition of Opuntia dillenii Haw. Methods Manykinds of chromatogra-phy methods were used in the isolation procedure, while the structures ofisolated compounds were determined on the aids of NMR and MS spectral analysis. Result Three newcompounds, together with 14 known compounds, were isolated form the 80% ethanolic extract of itsstems. Conclusion The three new compounds, opuntioside Ⅰ (2), 4-ethoxyl-6-hydroxymethyl-α-pyrone(3) and kaempferol 7-O-β-D-glucopyranosyl (1→4)-β-D-glucopyranoside (4), were characterized.
基金Project supported by the National Natural Science Foundation of China(21102035)Natural Science Item of Education Department of Henan Province(14A180030)