Alkylative epoxide rearrangement. A stereospecific approach to chiral epoxide pheromones
摘要:
The alkylative rearrangement of 1,2-epoxy-3-alkanol tosylates is applied to the synthesis of chiral epoxide pheromones. Attack at the terminal carbon atom of epoxy tosylates by lithioacetylenes and cyclization of the intermediate tosyloxy alcohols produces internal epoxides in high yield. The method is stereospecific: threo-epoxy tosylates give eL's-epoxides, and erythro-epoxy tosylates yield trans-epoxides. Several diastereomerically pure epoxides were prepared in high optical purity from chiral pool intermediates derived from sugars. Pheromone components prepared include (+/-)-cis-epoxyalkene 20 and both enantiomers of cis-epoxy diene 16, a female sex pheromone component of a number of lepidopteran species. These results demonstrate that alkylative rearrangement of 1,2-epoxy-3-alkanol tosylates complements existing methods for stereoselective synthesis of epoxides, including the Payne rearrangement and Sharpless epoxidation.
Short and Versatile Two-Carbon Ring Expansion Reactions by Thermo-Isomerization: Novel Straightforward Synthesis of (±)-Muscone, Nor- and Homomuscones, and Further Macrocyclic Ketones
作者:Matthias Nagel、Hans-Jürgen Hansen、Georg Fráter
DOI:10.1055/s-2002-19759
日期:——
the ring-expanded ketone as corresponding α-, and β-substituents, respectively. This novel thermal 1,3-C shift reaction therefore provides a new access to short syntheses of many alkyl-substituted macrocyclic ketone derivatives [e.g. (′)-muscone and analogues] in a systematic manner.
在 600 °C 至约 650 °C 的温度下,1-乙烯基取代的中环和大环环烷醇衍生物在流动反应器系统中的热异构化直接导致扩环大环酮。乙烯基部分的烷基取代基分别作为相应的α-和β-取代基局部特异性地转移到扩环的酮上。因此,这种新颖的热 1,3-C 变换反应为许多烷基取代的大环酮衍生物 [例如 (')-麝香酮和类似物] 以系统方式进行短程合成提供了新途径。
Nanosized gold-catalyzed selective oxidation of alkyl-substituted benzenes and n-alkanes
作者:Ankush V. Biradar、Tewodros Asefa
DOI:10.1016/j.apcata.2012.05.029
日期:2012.9
silica-supported gold nanoparticles efficiently catalyzed the oxidation reactions of different alkyl-substituted benzenes and linear alkanes with t-butyl hydroperoxide (TBHP) as an oxidant. The catalytic reactions gave up to ∼99% reactant conversion and up to ∼100% selectivity toward ketone products in some cases. This high selectivity toward ketone products by the catalysts was unprecedented, especially
Organoruthenium‐Supported Polyoxotungstate – Synthesis, Structure and Oxidation of
<i>n</i>
‐Hexadecane with Air
作者:Rui‐Qi Meng、Bin Wang、Hui‐Min Sui、Bao Li、Wei Song、Li‐Xin Wu、Bing Zhao、Li‐Hua Bi
DOI:10.1002/ejic.201201037
日期:2013.4
sandwich-type structure, which is further connected by K cations to construct the 3D structures. Based on complex Ru-KNa, the compound Ru-Na was synthesized, and it consists of two Ru(C6H6)} units linked to a [W8O28(OH)2]10– fragment by three Ru–O(W) bonds to result in an assembly with idealized C2 symmetry in which the polyanions form 3D structures by the connection of Na chains. Subsequently, the compound Ru-Na
钌配合物 KNa[Ru2(C6H6)2(CH3COO)6] (Ru-KNa) 及其多氧钨酸盐衍生物 Na6[Ru(C6H6)}2W8O28(OH)2]·16H2O (Ru-Na)成功地从常规合成反应中分离出来,并通过 X 射线单晶结构分析、红外光谱和元素分析进行表征。Ru-KNa 的一个显着方面是它有两种配体类型,苯和乙酸盐,乙酸盐配体仅通过一个中心 Na 阳离子连接形成二聚体夹心型结构,该结构通过 K 阳离子进一步连接以构建3D 结构。以络合物Ru-KNa为基础,合成了化合物Ru-Na,它由两个 Ru(C6H6)} 单元组成,通过三个 Ru-O(W) 键连接到 [W8O28(OH)2]10– 片段,从而形成具有理想化 C2 对称性的组件,其中聚阴离子形成 3D 结构通过 Na 链的连接。随后,将化合物 Ru-Na 锚定在(3-氨基丙基)三乙氧基硅烷(apts)改性的 SBA-15
Cycloalkanones. 8. Hypocholesterolemic activity of long-chain ketones related to pentadecanone
作者:Steven D. Wyrick、Iris H. Hall、Claude Piantadosi、Charles R. Fenske
DOI:10.1021/jm00224a005
日期:1976.2
Aliphatic analogs of 2,8-dibenzylcyclooctanone which includes C15-C18 ketones have been investigated for hypocholesterolemicactivity in rats. The position of the carbonyl group in the chain for maximum activity appears to be the 2 position. 2-Hexadecanone reduced serum cholesterol levels significantly without altering serum triglyceride levels. This drug was not estrogenic at effective doses which
The present invention is directed to novel cyclopropanated macrocyclic ketone and lactone compounds of the general formula
wherein X is an atom or a functional group selected from the group consisting of 0, N, S, CH, or CH
2
; wherein Y is a straight or branched hydrocarbon moiety consisting of 1 to 20 carbon atoms; wherein W is a straight or branched hydrocarbon moiety of consisting of 1 to 20 carbon atoms; and wherein O is an oxygen atom; and the use of these novel compounds in creating fragrances, and scents in items such as perfumes, colognes and personal care products.