The selective epoxidation of 3,3-(1,2-ethanediyl-bisoxy)-5(10),9(11)-estradiene-17-α-(1-propynyl)-17-β-ol with Fe(Ⅱ)Pc/PhIO was investigated at 25 ℃? atmospheric pressure. With a molar ratio of Fe(Ⅱ)Pc∶compound...The selective epoxidation of 3,3-(1,2-ethanediyl-bisoxy)-5(10),9(11)-estradiene-17-α-(1-propynyl)-17-β-ol with Fe(Ⅱ)Pc/PhIO was investigated at 25 ℃? atmospheric pressure. With a molar ratio of Fe(Ⅱ)Pc∶compound(I)∶PhIO at 6.25∶50∶120, the conversion reaches 100%. The overall yield of the products 5α, 10α-epoxide(2) and 5β, 10β-epoxide(3)is 60%, and the molar ratio of 2 to 3 is {8.39∶}1. The product 5α, 10α-epoxide is identified by melting point and HPLC.展开更多
This study demonstrated that damage to the cerebral microvasculature, the formation of microthrombi and swelling of vascular endothelial cells occur early and peak 12 hours after injury in a rat model of diffuse axona...This study demonstrated that damage to the cerebral microvasculature, the formation of microthrombi and swelling of vascular endothelial cells occur early and peak 12 hours after injury in a rat model of diffuse axonal injury. Moreover, these pathological changes were most evident in the cerebral cortex. Cerebral microcirculatory dysfunction peaked later and had a shorter duration than axonal injury. In addition, the radioactive imaging agent, 99Tcm-4, 9-diaza-2, 3, 10, 10- tetramethyldodecan-2, 11 -dione dioxime, was used to visualize the dynamic changes that occur in tissue with cerebral hypoxia. The results demonstrated that cerebral hypoxia occurs at an early stage in diffuse axonal injury. Cerebral hypoxia was evident 12 hours after injury and declined slightly 24 hours after injury, but was significantly higher than in the control group. The pathological changes that underpin microcirculatory dysfunction did not occur at the same time as axonal injury, but did occur simultaneously with neuronal injury. Cerebral hypoxia plays a key role in promoting the secondary brain injury that occurs after diffuse axonal injury.展开更多
The cycloaddition of N-acyliminium cations with some deactivated alkenes such as α,β-unsaturate ketones and esters has been investigated. In most cases, the N-acyliminium cations produced from 3-hydroxy-2-arylisoind...The cycloaddition of N-acyliminium cations with some deactivated alkenes such as α,β-unsaturate ketones and esters has been investigated. In most cases, the N-acyliminium cations produced from 3-hydroxy-2-arylisoindol-1-ones in the presence of BFa.OEt2 could be reacted with α,β-unsaturated ketones and esters to afford stereoselectively the cycloaddition products 6-acylisoindolo[2,1- a]quinolin-11-ones in moderate to high yields. C 2009 Wei Zhang. Published by Elsevier B.V, on behalf of Chinese Chemical Society. All rights reserved.展开更多
文摘The selective epoxidation of 3,3-(1,2-ethanediyl-bisoxy)-5(10),9(11)-estradiene-17-α-(1-propynyl)-17-β-ol with Fe(Ⅱ)Pc/PhIO was investigated at 25 ℃? atmospheric pressure. With a molar ratio of Fe(Ⅱ)Pc∶compound(I)∶PhIO at 6.25∶50∶120, the conversion reaches 100%. The overall yield of the products 5α, 10α-epoxide(2) and 5β, 10β-epoxide(3)is 60%, and the molar ratio of 2 to 3 is {8.39∶}1. The product 5α, 10α-epoxide is identified by melting point and HPLC.
基金the National Natural Science Foundationof China, No. 30471774the Program for New Century Excellent Talents in University, Ministry of Education,China, No. NCET-05-0831
文摘This study demonstrated that damage to the cerebral microvasculature, the formation of microthrombi and swelling of vascular endothelial cells occur early and peak 12 hours after injury in a rat model of diffuse axonal injury. Moreover, these pathological changes were most evident in the cerebral cortex. Cerebral microcirculatory dysfunction peaked later and had a shorter duration than axonal injury. In addition, the radioactive imaging agent, 99Tcm-4, 9-diaza-2, 3, 10, 10- tetramethyldodecan-2, 11 -dione dioxime, was used to visualize the dynamic changes that occur in tissue with cerebral hypoxia. The results demonstrated that cerebral hypoxia occurs at an early stage in diffuse axonal injury. Cerebral hypoxia was evident 12 hours after injury and declined slightly 24 hours after injury, but was significantly higher than in the control group. The pathological changes that underpin microcirculatory dysfunction did not occur at the same time as axonal injury, but did occur simultaneously with neuronal injury. Cerebral hypoxia plays a key role in promoting the secondary brain injury that occurs after diffuse axonal injury.
基金the National Natural Science Foundation of China(No.20872056) for financial support.
文摘The cycloaddition of N-acyliminium cations with some deactivated alkenes such as α,β-unsaturate ketones and esters has been investigated. In most cases, the N-acyliminium cations produced from 3-hydroxy-2-arylisoindol-1-ones in the presence of BFa.OEt2 could be reacted with α,β-unsaturated ketones and esters to afford stereoselectively the cycloaddition products 6-acylisoindolo[2,1- a]quinolin-11-ones in moderate to high yields. C 2009 Wei Zhang. Published by Elsevier B.V, on behalf of Chinese Chemical Society. All rights reserved.
