Baogongteng A is a tropane alkaloid with cholinergic activity. It has been used clinically for the treatment of glaucoma, and its pharmacological activity on heart function has also been reported.In the synthesis of b...Baogongteng A is a tropane alkaloid with cholinergic activity. It has been used clinically for the treatment of glaucoma, and its pharmacological activity on heart function has also been reported.In the synthesis of baogongteng A, the cycloadducts of Katritzky cycloaddition of 1-benzyl-3-oxidepyridinium with a-chloroacrylonitrile were ketalized with ethylene glycol in benzene by azeotropic distillation. After recrystallization from ethanol, two compounds（A, prisms, m.p.127—129℃; B, needles, m.p.75—77℃） were obtaines.Their MS, IR spectral data and elemental analysis were consistent with the proposed structures. They were assigned as C<sub>6</sub>-chloro nitrile epimers by <sup>1</sup>H-<sup>1</sup>H展开更多
Since the study of the nuclear magnetic resonance （NMR）spectra of a number of sixmembered ring compounds reported by Lemieux et al. in 1958, the chemical shift and coupling constant for H<sub>1</sub> hav...Since the study of the nuclear magnetic resonance （NMR）spectra of a number of sixmembered ring compounds reported by Lemieux et al. in 1958, the chemical shift and coupling constant for H<sub>1</sub> have been used extensively to identify anomeric isomers in carbohydrate compounds. In 1-O-acyl-tetra-O-acetyl-β-O-hexapyranose, the anomeric proton of the展开更多
文摘Baogongteng A is a tropane alkaloid with cholinergic activity. It has been used clinically for the treatment of glaucoma, and its pharmacological activity on heart function has also been reported.In the synthesis of baogongteng A, the cycloadducts of Katritzky cycloaddition of 1-benzyl-3-oxidepyridinium with a-chloroacrylonitrile were ketalized with ethylene glycol in benzene by azeotropic distillation. After recrystallization from ethanol, two compounds（A, prisms, m.p.127—129℃; B, needles, m.p.75—77℃） were obtaines.Their MS, IR spectral data and elemental analysis were consistent with the proposed structures. They were assigned as C<sub>6</sub>-chloro nitrile epimers by <sup>1</sup>H-<sup>1</sup>H
文摘Since the study of the nuclear magnetic resonance （NMR）spectra of a number of sixmembered ring compounds reported by Lemieux et al. in 1958, the chemical shift and coupling constant for H<sub>1</sub> have been used extensively to identify anomeric isomers in carbohydrate compounds. In 1-O-acyl-tetra-O-acetyl-β-O-hexapyranose, the anomeric proton of the
