A general method for the synthesis of enantiopure aliphatic chain alcohols with established absolute configurations. Part 1. Application of the MαNP acid method to acetylene alcohols
applied to various acetylenealcohols 4–12 and 14. In the case of MαNP esters 21b, 24a, and 26a, their absoluteconfigurations were unambiguously determined by X-ray crystallography, which confirmed the absoluteconfiguration assignments performed by 1H NMR anisotropy. These acetylenealcohol MαNP esters can serve as key intermediates for the synthesis of enantiopure aliphatic chain alcohols with established
使用(A方法小号(+) - - )2-甲氧基-2-(1-萘基)丙酸1(MαNP酸)已经施加到炔属醇4 - 14由以确定它们的绝对构型1个1 H NMR各向异性和/或X射线晶体学。从外消旋乙炔醇和(非对映体制备酯MαNP小号(+) - - )MαNP酸1是易于分离的,通过HPLC在硅胶上。从1 1 H NMR各向异性Δ δ分离非对映体MαNP酯Δ数据δ = δ([R ,X) - δ(小号,X)= δ(第二FR) - δ(第一FR)},第一洗脱酯的绝对构型进行测定。此MαNP酸方法已成功地应用于各种乙炔醇4 - 12和14。在MαNP酯的情况下21B,24A,和26A,它们的绝对构型通过明确地X射线晶体学,这证实所执行的绝对构型确定分配11 H NMR各向异性。这些炔属醇MαNP酯可以如在本系列的第2部分中描述作为对映体纯的脂肪族链醇既定绝对构型的合成的关键中间体。
Gold(I)-catalysed synthesis of cyclic sulfamidates: current scope, stereochemistry and competing ene-allene cycloisomerisation
作者:Mari C.M. Higginbotham、Lorna Kennedy、Anita G. Lindsay、Andreas Troester、Magnus W.P. Bebbington
DOI:10.1016/j.tet.2014.11.058
日期:2015.1
Six-membered cyclic sulfamidates are prepared in high yields by treatment of allenic sulfamates with readily available Ph3PAuNTf2. The reaction enables formation of N-substituted quaternary centres in high yields. The relative stereochemistry has been unambiguously determined. A π-rearrangement is faster than hydroamination in the case of an allyl-substituted sulfamate and a mechanism is proposed for
Gold(III) catalyzed stereoselective synthesis of dialkyl dihydrofuran acetates
作者:Sagarika Behera、Nabakumar Bera、Debayan Sarkar
DOI:10.1016/j.tet.2021.132367
日期:2021.8
A gold (III) catalyzed stereoselective cycloisomerization of 5-disubstituted-5-hydroxypent-2-yn alkanoate is described. The mild and efficient reaction condition delivers a series of di, tri-substituted dihydrofuran derivatives with high yield s along with an impressive diastereoselectivity. The reaction proceeds via a double [3,3] sigmatropic rearrangement with a concomitant 5-endo-dig cyclization
Synthesis of dihydrofuran-3-one and 9,10-phenanthrenequinone hybrid molecules and biological evaluation against colon cancer cells as selective Akt kinase inhibitors
10-phenanthrenequinone hybrid compounds were synthetized through a one-pot gold-catalyzed oxidative cyclization and Aldol-type addition cascade reaction of homopropargylic alcohols with 9,10-phenanthrenequinone. The cytotoxicity of newly synthesized compounds was evaluated in CCK8 assay against different human cancer cells, showing significantly antiproliferative activityagainst tested tumor cell lines
The Prevalence of Daytime Napping and Its Relationship to Nighttime Sleep
作者:June J. Pilcher、Kristin R. Michalowski、Renee D. Carrigan
DOI:10.1080/08964280109595773
日期:2001.1
Many healthy adults report daytime napping. Surprisingly few studies, however have examined spontaneous napping behavior especially very short naps, in healthy adults. The authors examined the prevalence of power naps (lasting less than 20 minutes) and longer naps (20 minutes or more) and their effects on nighttime sleep in a group of healthy young and middle-aged adults. The young and middle-aged adults reported very similar sleep and napping patterns, with approximately 74% of the participants in both groups reporting they had napped during a 7-day sleep-log period. Almost half of the participants reported that the average nap lasted less than 20 minutes. A multivariant analysis of variance (MANOVA) found no significant differences between the no-nap and the power-nap or long-nap groups in sleep quantity or quality for either age group. The current data suggested that power napping occurs frequently in healthy adults and that spontaneous napping does not negatively affect nighttime sleep.