Selective Catalytic Hydrogenations and Hydrogenolyses VIII [1]: Stereoselective Synthesis of the Stereomeric Pilopyl Alcohols
摘要:
The stereoselective synthesis of pilopyl- and isopilopyl alcohol is reported. The reaction of dimethyldioxanone and diethoxyphosphoryl-butyric acid ethyl ester afforded the corresponding dioxanylidenbutyric acid ester as the key intermediate. Upon treatment with mineral acid it cyclized giving 3-ethyl-4-hydroxymethylfuran-2-one which in turn could be converted either to 3-ethyl-4-methylfuranone or pilopyl alcohol with excellent stereoselectivity and quantitative chemical yield. On the other hand, hydrogenation and subsequent cyclization of the same key compound furnished isopilopyl alcohol with good stereomeric purity and yield.
本发明公开了一种毛果芸香碱的关键中间体合成方法,本发明提供了一种毛果芸香碱的关键中间体合成方法,本发明以2,2‑二甲基‑1,3‑二噁烷‑5‑酮为起始原料,经过Horner‑Wadsworth‑Emmons烯烃化、水解、氧化、Wittig反应、水解、氧化等步骤合成4‑乙基‑5‑氧‑2,5‑二氢呋喃‑3‑乙酸,再按照《Concise Synthesis of Both Enantiomers of Pilocarpine》的文献中的步骤合成最终产品。
[DE] FURANONSYNTHESE<br/>[EN] FURANONE SYNTHESIS<br/>[FR] SYNTHESE DE FURANONES
申请人:MERCK PATENT GMBH
公开号:WO2003051857A2
公开(公告)日:2003-06-26
Gegenstand der vorliegenden Erfindung ist Verfahren zur Herstellung von Furanonen der Formel (I), bei dem von einer Verbindung der Formel (II) ausgegangen wird, die Verbindungen der Formel (I) sowie deren Verwendung zur Herstellung von Furanonderivaten gemäss Formel (III).
Selective Catalytic Hydrogenations and Hydrogenolyses VIII [1]: Stereoselective Synthesis of the Stereomeric Pilopyl Alcohols
作者:Eberhard Reimann、Manfred Renz [2]、Helene Unger
DOI:10.1007/s00706-002-0484-9
日期:2002.9.1
The stereoselective synthesis of pilopyl- and isopilopyl alcohol is reported. The reaction of dimethyldioxanone and diethoxyphosphoryl-butyric acid ethyl ester afforded the corresponding dioxanylidenbutyric acid ester as the key intermediate. Upon treatment with mineral acid it cyclized giving 3-ethyl-4-hydroxymethylfuran-2-one which in turn could be converted either to 3-ethyl-4-methylfuranone or pilopyl alcohol with excellent stereoselectivity and quantitative chemical yield. On the other hand, hydrogenation and subsequent cyclization of the same key compound furnished isopilopyl alcohol with good stereomeric purity and yield.
Unexpected Isomerization of Oxetane-Carboxylic Acids
作者:Bohdan Chalyk、Anastasiia Grynyova、Kateryna Filimonova、Tymofii V. Rudenko、Dmitry Dibchak、Pavel K. Mykhailiuk
DOI:10.1021/acs.orglett.2c01402
日期:2022.7.8
Many oxetane-carboxylic acids were found to be unstable. They easily isomerized into new (hetero)cyclic lactones while being stored at room temperature or slightly heated. Chemists should keep in mind the high instability of these molecules, as this could dramatically affect the reaction yields and lead to negative results (especially in those reactions that require heating).