A novel, stereodivergent route to paraconic acids from C 2-symmetric trans- and cis-alk-2-ene-1,4-diols through Ireland-Claisen and/or Johnson orthoester rearrangements is disclosed. This strategy has been applied to the synthesis of (-)-methylenolactocin and (-)-phaseolinic acid from a single chiral diol.
Pd-supported catalysts are fundamental tools in organic reactions involving H2 splitting. Here we show that 1,4-enediols enriched in one diastereoisomer are produced from the classical Pd-catalyzed semi-hydrogenation reaction with H2, starting from the corresponding, widely available 1,4-diacetylenic diols. The semi-hydrogenation reaction proceeds concomitantly with the desymmetrization of the meso/racemic
Pd负载的催化剂是涉及H 2分解的有机反应的基本工具。在这里,我们展示了富含一种非对映异构体的 1,4-烯二醇是通过经典的 Pd 催化与 H 2的半氢化反应生产的,从相应的、广泛使用的 1,4-二乙炔二醇开始。半氢化反应与烯二醇的内消旋/外消旋形式的去对称化同时进行。我们还表明,如果这些产品提前添加到 H 2中,则会使 Pd 催化剂完全失活(仅当在 H 2之前添加时)。这些结果提供了一种简单的方法,不仅可以通过经典催化方法生产富含一种非对映异构体的1,4-烯二醇,而且还可以阻止Pd纳米颗粒上的H 2解离。
Water soluble surfactant compositions
申请人:AIR PRODUCTS AND CHEMICALS, INC.
公开号:EP0618000A1
公开(公告)日:1994-10-05
This invention relates to water soluble wetting agents for use in aqueous systems based upon a mixture of an alkyl sulfosuccinate and an alkylene oxide adduct of an acetylenic alcohol. The mixture of sulfosuccinate and an alkylene oxide adduct of an acetylenic alcohol reduces surface tension and effects solubilization of the sulfur containing wetting agent.
A protective coating is provided. This protective coating comprises a synthetic resin solid content (A); and a mixture of (B-1) acetylene glycol represented by the following general formula (1):
and/or an ethoxylated derivative of the acetylene glycol represented by the following general formula (2):
and (B-2) at least one member selected from polyoxy(ethylene - propylene) block polymers represented by the following formula (3):
O(C2H4O)w(C3H6O)x(C2H4O)y(CH6O)zH (3).
Coating composition for a metal, and metal material having a coating of such coating composition
申请人:Nissin Chemical Industry Co., Ltd.
公开号:EP1897922A2
公开(公告)日:2008-03-12
A coating composition for a metal is provided. The coating composition comprises a coating composition for a metal comprising a synthetic resin solid content (A); a filler (B); and a mixture of (C-1) acetylene glycol represented by the following general formula (1):
and/or an ethoxylated derivative of the acetylene glycol represented by the following general formula (2):
and (C-2) at least one member selected from polyoxy(ethylene - propylene) block polymer represented by the following formula (3):
HO(C2H4O)w(C3H6O)x(C2H4O)y(C3H6O)zH (3).