共轭三烯是快速构建复杂多环化合物的令人着迷的构建模块。然而,由于具有挑战性的区域选择性控制,取得的成功有限。在此,我们报告了一种对映选择性和非对映选择性过程,可以区域选择性地控制N H-三烯-氨基甲酸酯的官能化。手性顺式-3,6-二氢-2H -1,2-恶嗪的合成是通过手性磷酸催化的亚硝基-Diels-Alder环加成反应实现的,涉及[(1 E ,3 E ,5 E )-hexa-1, 3,5-三烯-1-基]氨基甲酸酯。此外,通过仔细选择反应条件,可以模块化获得具有优异非对映选择性和高至优异对映选择性的三种不同区域异构体。计算研究表明,区域选择性受到三烯 6 位取代基的空间需求以及两个环加成伙伴之间的非共价相互作用的影响。各种合成转化突出了每种区域异构环加合物的实用性。
Relationship between anticoagulant medication and massive intraocular hemorrhage in age-related macular degeneration
作者:M. A. D. Tilanus、Willem Vaandrager、Marinus H. M. Cuypers、Adrianus M. Verbeek、Carel B. Hoyng
DOI:10.1007/pl00007887
日期:2000.6.20
Background: A massive intraocular hemorrhage in the course of age-related macular degeneration (AMD) is a devastating event. We set out to determine the role of anticoagulant therapy prescribed for vascular or cardiac indications in the development of a massive hemorrhage.Methods: A retrospective case-controlled study was conducted of 50 cases of age-related macular degeneration complicated by massive subretinal and vitreous hemorrhage. The control group consisted of 50 cases of AMD with small subretinal hemorrhage. Results: There was a significant difference in the use of anticoagulant medication (warfarin sodium) between the groups. The difference in the use of antiplatelet medication (aspirin) between the groups was not significant. A patient with a massive intraocular hemorrhage and AMD is 11.6 times more likely to use anticoagulant medication. It appeared that more than 50% of the patients in the massive hemorrhage group were allowed to stop the anticoagulant medication.Conclusion: Anticoagulant medication poses a significant risk in the development of a massive intraocular hemorrhage in patients with exudative AMD. Antiplatelet medication poses a less significant risk. Physicians prescribing anticoagulant medication should be informed about the macular status of the patient. the In case of neovascular AMD, anticoagulant medication should be prescribed only for absolute systemic indications.