Azetidin-2,3-dione Synthon for Stereoselective Synthesis of<i>cis-</i>and<i>trans-</i>C-3-Alkyl/Aryl Azetidin-2-ones
作者:Abdul Rakeeb Deshmukh、Dharmendra Kumar Tiwari、Vikas K. Gumaste
DOI:10.1055/s-2005-921746
日期:——
1,4-Bis-(4-methoxyphenyl)azetidin-2,3-dione has been prepared and used as a synthon for the stereoselective synthesis of C-3-alkyl/aryl azetidin-2-ones. Some of these are well known for their cholesterol absorption inhibitor activity. A regioselective Grignard reaction at a keto-group followed by highly stereoselective removal of the hydroxyl group via reductive removal of the xanthate ester is a key step in this synthesis. Base-induced isomerization of cis-azetidin-2-ones to the thermodynamically stable trans-isomer was also studied.
1,4-双(4-甲氧基苯基)哌啶-2,3-二酮已经被合成,并作为一种合成子用于C-3-烷基/芳基哌啶-2-酮的立体选择性合成。其中一些被广泛认识为具有胆固醇吸收抑制活性。该合成中的一个关键步骤是,在酮基进行区域选择性的格林纳反应,随后通过还原去除木香酸酯,高度立体选择性地去除羟基。此外,还研究了在碱性条件下,顺式哌啶-2-酮转变为热力学稳定的反式异构体的异构化反应。