Concise Entry to Both Enantiomers of 8-Oxabicyclo[3.2.1]oct-3-en-2-one Based on Novel Oxidative Etherification: Formal Synthesis of (+)-Sundiversifolide
摘要:
Both enantiomers of 8-oxabicyclo[3.2.1]oct-3-en-2-one (6) have been synthesized from 4-hydroxycyclohept-2-enone (3) on the basis of a novel oxidative cyclo-etherification using PhI(OH)OTs (Koser's reagent). (-)-(1S,5R)-8-Oxabicyclo[3.2.1]oct-3-en-2-one [(-)-6, 95% ee] was expeditiously transformed to (-)-sundiversifolide (1).
Allylic Oxidations Catalyzed by Dirhodium Catalysts under Aqueous Conditions
申请人:Doyle Michael P.
公开号:US20090093638A1
公开(公告)日:2009-04-09
The present invention relates to compositions and methods for achieving the efficient allylic oxidation of organic molecules, especially olefins and steroids, under aqueous conditions. The invention concerns the use of dirhodium (II,II) “paddlewheel complexes, and in particular, dirhodium carboximate and tert-butyl hydroperoxide as catalysts for the reaction. The use of aqueous conditions is particularly advantageous in the allylic oxidation of 7-keto steroids, which could not be effectively oxidized using anhydrous methods, and in extending allylic oxidation to enamides and enol ethers.
Intramolecular cyclization of bis-α-diazoketones: a new synthesis of 4-hydroxytropone
作者:J. Font、F. Serratosa、J. Valls
DOI:10.1039/c29700000721
日期:——
The catalytic decomposition of bis-α-diazoketones, in inert solvents, under the high dilution conditions of Ruggli–Ziegler, affords cycloalk-2-ene-1,4-diones; the method was applied to the synthesis of 4-hydroxytropone (γ-tropolone).
Intramolecular cyclization of bis-α-diazoketones: A new synthesis of γ-tropolone
作者:J. Font、J. Valls、F. Serratosa
DOI:10.1016/s0040-4020(01)97023-1
日期:1974.1
Catalytic decomposition of bis-α-diazoketones (3, n = 3), in inert solvents, under high dilution affords cycloalk-2-ene-1,4-diones (4, n = 3). The method has been applied to a newsynthesis of γ-tropolone 5 in five steps from glutaconic acid 6.
Dirhodium(II) Caprolactamate: An Exceptional Catalyst for Allylic Oxidation
作者:Arthur J. Catino、Raymond E. Forslund、Michael P. Doyle
DOI:10.1021/ja045330o
日期:2004.10.1
The oxidation of organic molecules represents a fundamentally important chemical process. Particularly important is allylicoxidation, whereby a single methylene unit is converted directly into a carbonyl group. In this communication, we report that dirhodium(II) caprolactamate [Rh2(cap)4] in combination with tert-butyl hydroperoxide (terminal oxidant) effectively catalyzes the allylicoxidation of
有机分子的氧化是一个非常重要的化学过程。特别重要的是烯丙基氧化,由此单个亚甲基单元直接转化为羰基。在这篇通讯中,我们报告了己内酰胺二铑 (II) [Rh2(cap)4] 与叔丁基过氧化氢(末端氧化剂)结合有效地催化了各种烯烃和烯酮的烯丙基氧化。该反应是完全选择性的,可以耐受空气/水分,并且可以在几分钟内使用低至 0.1 mol% 的催化剂进行。已经提出了涉及氧化还原链催化的机制建议,以及更高价的叔丁基过氧化二铑络合物的中介作用的证据。
Palladium(0) catalyzed reaction of 1,3-diene 1,4-epiperoxides
作者:M. Suzuki、Y. Oda、R. Noyori
DOI:10.1016/s0040-4039(01)82971-3
日期:1981.1
Reaction of 1,3-diene 1,4-epiperoxides with Pd(PPh3)4 catalyst forms the corresponding 4-hydroxy enones, syn diepoxides, and 1,4-diols as the major products. The results are interpreted as being due to competing Pd(0)/Pd(II) and Pd(0)/Pd(I) exchange mechanisms.