The stereoselective construction of the CDEFGH ring system of lancifodilactone G is described. The key steps in this synthesis are (i) ring-closing metathesis for formation of the oxa-bridged eight-membered ring; (ii) an intramolecular Pauson–Khand reaction for construction of the sterically congested F ring; and (iii) sequential cross-metathesis, hydrogenation, and lactonization reactions for installation
Intramolecular Conjugate Displacement: A General Route to Hexahydroquinolizines, Hexahydroindolizines, and Related [<i>m</i>,<i>n</i>,0]-Bicyclic Structures with Nitrogen at a Bridgehead
作者:Derrick L. J. Clive、Zhiyong Li、Maolin Yu
DOI:10.1021/jo070664s
日期:2007.7.1
classical Morita−Baylis−Hillman reaction (cf. 2 → 3) or by condensation with selenium-stabilized carbanions, followed by oxidation (cf. 2 → 8 → 3). The derived acetates undergo cyclization when the nitrogen protecting group is removed, affording [m,n,0]-bicyclic structures with nitrogen at a bridgehead (cf. 4 → 5 → 6). Formation of bicyclic structures via the reactions of Schemes 1 and 2 is general,
A general method for making bicyclic compounds with nitrogen at a bridgehead—application to the halichlorine spiro subunit
作者:Derrick L. J. Clive、Maolin Yu、Zhiyong Li
DOI:10.1039/b413481h
日期:——
N-Protected β-amino aldehydes having the nitrogen in a ring are easily converted into MoritaâBaylisâHillman adducts; O-acetylation and N-deprotection result in spontaneous cyclization to bicyclic structures having nitrogen at a bridgehead.
氮位于环上的 N 保护δ-氨基醛很容易转化为莫里塔-贝利斯-希尔曼加合物;O-乙酰化和 N-脱保护可导致自发环化,形成氮位于桥头的双环结构。
Cyclohept[b]indoleakanoic acids, pharmaceutical compositions and use
申请人:Merck Frosst Canada, Inc.
公开号:US04906654A1
公开(公告)日:1990-03-06
Cyclohept[b]indolealkanoic acids and acid derivatives are disclosed. The compounds act as prostaglandin and thromboxane antagonists and are useful in treating asthma, diarrhea, hypertension, angina, platelet aggregation, cerebral spasm, premature labor, spontaneous abortion, dysmenorrhea and nephrotoxicity caused by cyclosporin A and as cytoprotective agents.
Cyclohept[b]indolealkanoic acids, pharmaceutical compositions and use
申请人:Merck & Co., Inc.
公开号:US04775680A1
公开(公告)日:1988-10-04
Cyclohept[b]indolealkanoic acids and acid derivatives are disclosed. The compounds act as prostaglandin and thromboxane antagonists and are useful in treating asthma, diarrhea, hypertension, angina, platelet aggregation, cerebral spasm, premature labor, spontaneous abortion, dysmenorrhea and nephrotoxicity caused by cyclosporin A and as cytoprotective agents.