Diastereotopic group selective intramolecular conjugate addition of 4-(2-hydroxyethyl)-p-quinol derivatives: Synthesis of the optically pure cis-7-oxabicyclo[4.3.0]non-2-en-4-one skeleton
摘要:
Diastereotopic group selective cyclization of 4-(2-hydroxyethyl)-p-quinol derivatives was achieved and the reaction applied to the synthesis of the optically pure cis-7-oxabicyclo[4.3.0]non-2-en-4-one skeleton.
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 。
Synthesis of trimethylsilyl carboxylates by HMDS under solvent-free conditions
作者:Marjan Jereb、Janja Lakner
DOI:10.1016/j.tet.2016.08.003
日期:2016.9
carboxylic acids were transformed into their trimethylsilyl esters with HMDS in a practically completely solvent-free process, while a catalytic amount of iodine was required in some cases. The process has several advantages over the known methods: untreated reactants, air atmosphere, mild and neutral conditions, no evolution of hydrogen halide, no need of an additional base, low amount of waste, completely