Highly regioselective intramolecular hydroxymethylation of α,β-unsaturated carboxylic acids
作者:Torsten Linker、Michael Maurer、Frank Rebien
DOI:10.1016/0040-4039(96)01931-4
日期:1996.11
A convenient synthesis of hydroxy esters 7 and lactones 8 by starting from easily available α,β-unsaturated carbocyclic acids 4 is described. The key step of this transformation is a hitherto unknown radical cyclization of silyl esters, which exhibits a high degree of regioselectivity through steric and orbital control.
Aqueous-phase hydrogenation of biomass-derived itaconic acid to methyl-γ-butyrolactone over Pd/C catalysts: Effect of pretreatments of active carbon
作者:Sha Li、Xicheng Wang、Xiaoran Liu、Guoqiang Xu、Sheng Han、Xindong Mu
DOI:10.1016/j.catcom.2014.12.017
日期:2015.2
The effect of active carbon pretreatment on the catalytic performance of Pd/C catalysts in the hydrogenation of itaconic acid was studied. The catalysts were prepared by deposition-precipitation and characterized by XRD, BET, NH3-TPD, TEM and FT-IR. Due to the modification of the surface functional groups, surface structure and surface acidities of active carbon via pretreatment, the Pd/C catalysts showed varied catalytic performances. High dispersion and uniform particles were conducive to the excellent activity of Pd/C catalyst with support copretreated with HNO3 and NaClO, which exhibited 89.5% selectivity towards methyl-gamma-butyrolactone at 180 degrees C, 4 MPa H-2 for 20 h. (C) 2014 Elsevier B.V. All rights reserved.
Sircar, Journal of the Chemical Society, 1928, p. 901
作者:Sircar
DOI:——
日期:——
Absolute konfiguration des steroidalkaloids solanocapsin an C-25
作者:K. Schreiber、H. Ripperger
DOI:10.1016/s0040-4039(01)99404-3
日期:1960.1
Partition coefficients of ketones, phenols, aliphatic and aromatic acids, and esters in n-hexane/nitromethane
作者:Urszula Kotowska、Valery Isidorov
DOI:10.2478/s11532-011-0060-4
日期:2011.10.1
in sample preparation and in countercurrent and liquid-liquid chromatographic separations. Partition coefficients are widely used in toxicology, environmental, and analytical chemistry. The K hn determination procedure for the n -hexane/nitromethane system was optimized and partition coefficients for 99 ketones, esters and trimethylsilyl derivatives of phenols, aliphatic and aromaticacids were determined
液-液分配用于样品制备以及逆流和液-液色谱分离。分配系数被广泛用于毒理学,环境和分析化学中。该 ķ HN 用于确定过程 Ñ 正己烷/硝基甲烷体系进行了优化和分配系数为99酮,酯和酚的三甲基甲硅烷衍生物,测定脂族和芳族酸。对于130种化合物, 使用 K hn 与其他理化和结构参数之间的数学关系来预测 K hn 值 。