Stereoselective Cyclization using Pd(II)-catalyst via Hemiacetal Intermediates and its Application to Sugar Synthesis

Pd(II) 催化剂通过半缩醛中间体的立体选择性环化及其在糖合成中的应用

• 批准号: 13640527
• 负责人: MIYAZAWA Masahiro
• 金额: $ 2.18万
• 依托单位: Toyama University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2001
• 资助国家: 日本
• 起止时间: 2001 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-13640527/
• 关键词: Palladium catalysy; Hemiacetal; Heterocyclization reaction; Glycosidation; Origo saccharides; Stereoselective; Ribose; DNA; 糖; スピロケタール

We recently reported the intramolecular substitution of an allyl alcohol by a heteroatom using a palladium (II) catalyst without activation of the allylic alcohol. We report here highly stereoselective intramolecular cyclization of 6- and 7-formyl allylic alcohols using palladium (II) catalyst in the presence of alcohol via unstable hemiacetal intermediates, in which cyclization occurs without activation of the allylic alcohol in this case too.1. Stereoselective Cyclization using Pd (II)-catalyst via Hemiacetal IntermediatesTreatment of 7-hydroxy-3-phenyl-5-hexenal with 5 mol% bis(benzonitrile)palladium (II) chloride in THF in the presence of primary, secondary, and tertiary alcohol afforded 6-membered cyclic acetals in 50〜80% yield with highly stereoselectivity. Especially, the relative stereochemistry at C4 and C6 position was 100% cis-selective by treatment with secondary and tertiary alcohols.2. Total synthesis of D-riboseA total synthesis of the furanose form of D-ribose, which is … More component of RNA, is described. The optically active cyclized precursor was prepared from (Z)-2-butene-I,4-diol using asymmetric esterification in 13 steps. Treatment of the precursor with Pd (II) catalyst gave the cyclized product Finally, D-ribose was prepared from the cyclized product in 2 steps.3. Total synthesis of 2-deoxy-D-riboseA total synthesis of the furanose form of 2-deoxy-D-ribose, which is component of DNA, is described. Preparation of the cyciized precursor required 8 steps and proceeded in 53% overall yield from (S)-malic acid. Treatment of the precursor with Pd (II) catalyst gave the cyclized product with good stereoselectivity. 2-Deoxy-D-ribose was prepared from the cyclized product in 5 steps.4. Synthetic studies of Origo saccharidesA disaccharide was obtained under mild conditions through palladium (II) catalyzed coupling reaction of the cyclized precursor and 2-deoxy-D-ribose derivative. The present method should provide a powerful tool in organic synthesis including carbohydrate synthesis. Less

我们最近报道了烯丙醇分子内取代的杂原子使用钯（II）催化剂，而不活化的烯丙醇。我们在这里报告高度立体选择性的分子内环化6-和7-甲酰基烯丙醇使用钯（II）催化剂在醇的存在下通过不稳定的半缩醛中间体，其中环化发生在这种情况下没有激活的烯丙醇。在伯、仲、叔醇存在下，7-羟基-3-苯基-5-己烯醛与5mol%氯化双（苄腈）钯（II）在THF中反应，以50 ~ 80%的产率高立体选择性地得到6元环缩醛。特别是在C4和C6位的相对立体化学是100%顺式选择性的仲醇和叔醇处理. D-核糖的全合成D-核糖的呋喃糖形式的全合成， ...更多信息 描述了RNA的组成部分。以（Z）-2-丁烯-1，4-二醇为原料，经不对称酯化反应，经13步反应合成了光学活性的环化前体。用Pd（II）催化剂处理前体得到环化产物，最后由环化产物经两步反应制备D-核糖. 2-脱氧-D-核糖的全合成描述了作为DNA组分的2-脱氧-D-核糖的呋喃糖形式的全合成。环化前体的制备需要8步，并且以53%的总收率从（S）-苹果酸进行。用Pd（II）催化剂处理前体得到具有良好立体选择性的环化产物。环化产物经5步反应制得2-脱氧-D-核糖. Origo糖的合成研究在温和的条件下，通过钯（II）催化的环化前体与2-脱氧-D-核糖衍生物的偶联反应得到二糖。本发明的方法将为包括碳水化合物合成在内的有机合成提供强有力的工具。少