Organocatalytic Enantioselective Pictet–Spengler Reaction of α‐Ketoesters: Development and Application to the Total Synthesis of (+)‐Alstratine A
作者:Rémi Andres、Fenggang Sun、Qian Wang、Jieping Zhu
DOI:10.1002/anie.202213831
日期:2023.1.2
The reaction of tryptamine with α-ketoesters in the presence of a catalytic amount of a chiral alanine-derived squaramide and 4-nitrobenzoic acid afforded the corresponding 1-alkyl-1-methoxycarbonyl tetrahydro-β-carbolines (THBCs) in high yields and ee values. A concise seven-step asymmetric total synthesis of alstratine A, a cagelike hexacyclic indole alkaloid, was developed featuring this enantioselective
在催化量的手性丙氨酸衍生角酰胺和 4-硝基苯甲酸存在下,色胺与 α-酮酯反应得到相应的 1-烷基-1-甲氧基羰基四氢-β-咔啉 (THBC),产率和ee值。笼状六环吲哚生物碱 alstratine A 的简明七步不对称全合成以这种对映选择性 Pictet-Spengler 反应为关键步骤。
METHOD FOR PURIFYING PYRUVIC ACID COMPOUNDS
申请人:SUMITOMO CHEMICAL COMPANY LIMITED
公开号:EP0937703A1
公开(公告)日:1999-08-25
The present invention is directed to a method for purifying pyruvic acid compounds, which method comprises reacting a pyruvic acid compound of general formula (I):
wherein R1 is an optionally substituted lower alkyl group, a lower alkenyl group, a lower alkynyl group, a cycloalkyl group, an aryl group, or a heterocyclic group, and R2 is a lower alkyl group, with a bisulfite of general formula (II):
MHSO3 (II)
wherein M is NH4 or an alkali metal, to give a bisulfite adduct of the pyruvic acid compound and then decomposing the adduct with an acid. According to the present invention, pyruvic acid compounds can be purified by simple and easy procedures without using purification techniques such as distillation or column chromatography, and the above method is advantageous as a process for the production on an industrial scale.
本发明涉及一种纯化丙酮酸化合物的方法,该方法包括使通式(I)的丙酮酸化合物反应:
其中 R1 是任选取代的低级烷基、低级烯基、低级炔基、环烷基、芳基或杂环基,R2 是低级烷基,与通式(II)的亚硫酸氢盐反应:
MHSO3 (II)
其中 M 为 NH4 或碱金属,以得到丙酮酸化合物的亚硫酸氢盐加合物,然后用酸分解该加合物。根据本发明,丙酮酸化合物可以通过简单易行的程序进行纯化,而无需使用蒸馏或柱层析等纯化技术,上述方法作为一种工业规模的生产工艺是非常有利的。
Lapkin,I.I. et al., Journal of Organic Chemistry USSR (English Translation), 1975, vol. 11, p. 2317 - 2319