Cyclisation of acetylenecarboxylic acid. Synthesis of γ-methylenebutyrolactones
作者:Makoto Yamamoto
DOI:10.1039/p19810000582
日期:——
Various γ-exo-methylenebutyrolactones have been synthesized in excellent yield by the cyclisation of acetylenecarboxylicacids in the presence of a catalytic amount of mercury(II) oxide. Cyclisation of terminal acetylene compounds[e.g.(1a)–(1e)]proceeded regioselectively to give γ-exo-methylenebutyrolactones as the sole product. Disubstituted acetylenes [(1f)–(1i)] also gave the (Z)-configurational
An unusual result of the reaction of α-acetylene aldehydes, pyridines, and malonic acid. Synthesis and structure of novel pyridine betaines
作者:Aleksander А. Golovanov、Sergei А. Dan’kov、Sergey А. Sokov、Pavel А. Melnikov、Anton I. Ukolov、Evgeniya D. Voronova、Anna V. Vologzhanina、Aleksander S. Bunev
DOI:10.1007/s10593-019-02424-6
日期:2019.1
5-Aryl-2-carboxy-5-(pyridin-1-ium-1-yl)penta-2,4-dienoates, previously unknown pyridine betaines, were formed in 32–70% yields as a result of the reaction of arylpropynals, substituted pyridines, and malonic acid instead of the expected 5-arylpent-2-en-4-ynoic acids. The molecular structure of the novel compounds was studied by X-ray structural analysis.
4-aminobiphenyl derivative arylamine compounds are formed by providing an iodinated organic compound; substituting the iodinated organic compound at carboxylic acid groups thereof to provide ester protecting groups; conducting an Ullman condensation reaction to convert the product of step (ii) into an arylamine compound; and conducting a Suzuki coupling reaction to add an additional phenyl group to the arylamine compound in the 4-position relative to the nitrogen.
The present invention provides a device for modifying an atmosphere in proximity to the device, the device comprising a sachet comprising a semipermeable material, and a composition including a mixture of acetylsalicylic acid and sodium bicarbonate contained within a cavity of the sachet. The invention further provides methods for modifying an atmosphere comprising placing a mixture of a carboxylic acid and a base in the atmosphere, wherein the atmosphere has a sufficient level of water vapor such that, upon contact of the water vapor with the mixture, carbon dioxide is produced.
A method and means for enhancing the inner environment of a package containing perishable merchandise include taking a closable package containing perishable merchandise and placing in the package a multi-layered sheet including a plurality of layers comprised of moisture absorbing materials to absorb any residual moisture emanating from the perishable merchandise. The multi-layered sheet includes a quantity of CO
2
generating material incorporated therein. The CO
2
generating material is exposable to humidity and any residual moisture within the package and any moisture absorbing material to allow the CO
2
generating material to emit an atmosphere of CO
2
within the package from exposure to moisture within the air in the package, and to absorb any residual moisture in the package.
一种用于改善装有易腐商品的包装内部环境的方法和装置,包括取一个装有易腐商品的可封闭包装,并在包装内放置一个多层薄片,该多层薄片包括由吸湿材料组成的多层,以吸收易腐商品散发出的任何残余湿气。多层板包括一定量的 CO
2
生成材料。二氧化碳
2
生成材料可暴露于湿度、包装内的任何残留湿气以及任何吸湿材料中,使 CO
2
生成材料释放出二氧化碳气体。
2
并吸收包装内的任何残留湿气。