Regio- and Stereoselective Preparation of β,γ-Unsaturated Carboxylic Acids by One-Pot Sequential Double 1,6-Addition of Grignard Reagents to Methyl Coumalate
An efficient regio‐ and stereoselective metal‐catalyzed addition of two Grignard reagents (homo‐coupling, 2 RMgX or hetero‐coupling, R1MgX+R2MgX) to methyl coumalate (methyl 2‐oxo‐2H‐pyran‐5‐carboxylate) is described. This synthetic approach opens the access to a wide variety of functionalized β,γ‐unsaturated carboxylic acids in a modular way. Control of the chemo‐ and stereoselectivity of this one‐pot
将两种格氏试剂(均偶联,2 RMgX或杂偶联,R 1 MgX + R 2 MgX)有效地在区域和立体选择性金属催化下添加到香豆酸甲酯(甲基2-氧代-2 H-吡喃-5-描述)。这种合成方法以模块化的方式为人们提供了多种功能化的β,γ-不饱和羧酸的途径。讨论了此一锅法化学和立体选择性的控制方法。
Stereoselective synthesis of conjugated α-Z/γ-E and α-Z/γ-Z dienoic acids. Kinetic torquoselectivity versus thermodynamic control
The stereoselective synthesis of conjugated (α-Z/γ-E)-(α-Z/γ-Z)-dienoic acids 4 and 4′ is described. It is based on the regio- and stereoselectiveaddition of Grignardreagents to methylcoumalate. The origin of the stereocontrol is discussed.
描述了共轭(α- Z /γ- E)-(α- Z /γ- Z)-二烯酸4和4'的立体选择性合成。它基于将格氏试剂在立体香豆素中的区域选择性和立体选择性加成。讨论了立体声控制的起源。