The regioselectivity of tributyltin ether-mediated benzylation of 1,6-anhydro-β-d-hexoipyranoses
作者:M. Carmen Cruzado、Manuel Martin-Lomas
DOI:10.1016/0008-6215(88)84142-9
日期:1988.5
Abstract The benzylation of 1,6-anhydro-β- d -galactopyranose and the manno , allo , altro , gulo , talo , gluco , and ido isomers, using bis(tributyltin) oxide and N -methylimidazole, tetrabutylammonium bromide, tetrabutylammonium iodide, or tetrabutylammonium fluoride as catalyst, has been studied. The results confirm the importance of the catalyst in the benzylation reactions and indicate that the
have established a direct and efficient synthetic method of deuterated sugars from non‐labeled sugars by using the heterogeneous Ru/C‐catalyzed H–D exchange reaction in D2O under a hydrogen atmosphere with perfect chemo‐ and stereoselectivities. The direct H–D exchange reaction can selectively proceed on carbons adjacent to the free hydroxyl groups, and the deuterium labeling of various pyranosides (such
氘标记的糖由于其潜在的特性,可以用作核酸和糖蛋白代表的含糖高分子的结构分析的强大工具,也可以用作合成新药物候选物(重药物)的手性构件,如简化1 1 H NMR谱和C的稳定性以C相比d键 H键。我们通过在D 2中使用异质Ru / C催化的H–D交换反应,建立了一种直接有效的从未标记糖中合成氘代糖的方法。在氢气氛下具有理想的化学和立体选择性的O。直接的H-D交换反应可以选择性地在与游离羟基相邻的碳上进行,从而实现了以核糖和脱氧核糖为代表的各种吡喃糖苷(如葡萄糖和二糖)以及呋喃糖苷的氘标记。此外,通过使用乙缩醛型保护基团对羟基进行位点选择性保护,可以将所需数量的氘原子自由地结合到所选位置,因为氘交换反应不会在受保护羟基附近的位置进行。
[EN] EXTERNAL PREPARATION FOR SKIN<br/>[FR] PREPARATION EXTERNE POUR LA PEAU
申请人:SHOWA DENKO KK
公开号:WO2005094777A1
公开(公告)日:2005-10-13
The present invention provides an external preparation for skin, which comprises a multi-branched polysaccharide derivative with multi-branched polysaccharide skeleton consisting of saccharides as constituent units, wherein at least one of hydroxyl (OH) groups in the multi-branched polysaccharide skeleton is substituted by OR (wherein R represents a hydrogen atom, a hydrocarbon having 1 to 30 carbon groups or a hydrocarbon having 1 to 30 carbon groups which has hetero atom), which can give moisture and turgor to the skin, and cosmetics containing the external preparation.
A process for producing D-allosan (IV) from levoglucosenone (I) in a high yield, which comprises reducing the 2-carbonyl group of levoglucosenone, inverting the configuration of the resultant hydroxyl group from α to β, protecting it by acylation to give a compound (III), conducting α-cis addition of two hydroxyl groups to the double bond of the compound (III), and removing the protective group.
The present invention provides a polysaccharide/functional compound complex comprising a functional compound and a multi-branched polysaccharide derivative, wherein the multi-branched polysaccharide derivative has a skeleton of a multi-branched polysaccharide composed of a saccharide as a structural unit, and at least one of the hydroxyl groups (OH) of the multi-branched polysaccharide is substituted by OR, wherein R represents a hydrogen atom, a hydrocarbon having 1 to 30 carbon atoms, or a hydrocarbon having 1 to 30 carbon atoms and hetero atom. The functional compound can be efficiently incorporated into polysaccharide derivative, and further by exposing the polysaccharide complex to an environment such as a solution, sustained release of the functional compound can be controlled. By utilizing this property, the complex can be efficiently used in external preparations for skin such as cosmetic products.
本发明提供了一种多糖/功能化合物复合物,该复合物包括功能化合物和多支链多糖衍生物,其中多支链多糖衍生物具有以糖为结构单元组成的多支链多糖骨架、多支链多糖的至少一个羟基(OH)被 OR 取代,其中 R 代表氢原子、具有 1 至 30 个碳原子的烃或具有 1 至 30 个碳原子和杂原子的烃。功能化合物可以有效地与多糖衍生物结合,通过将多糖复合物暴露在溶液等环境中,还可以控制功能化合物的持续释放。利用这一特性,该复合物可有效地用于化妆品等皮肤外用制剂中。