Stereoselective oxy-homo-Michael reactions of enantioenriched bicyclic donor–acceptor cyclopropanes to afford optically active trans-α,β-disubstituted γ-butyrolactones possessing three serial chiral centers
作者:Seijiro Takada、Kiitsu Iwata、Toshihide Yubune、Yoshinori Nishii
DOI:10.1016/j.tetlet.2016.04.076
日期:2016.6
carboxylic acid to optically active bicyclic donor–acceptor cyclopropanes such as (1S,5R,6S)-6-aryl-1-methoxycarbonyl-3-oxabicyclo[3,1,0]hexan-2-ones proceeded to give trans-α,β-disubstituted γ-butyrolactones, which possess three serial chiral centers, in good to high yields with excellent dr and ee. Increasing the loading of alcohols to two equivalents improved the diastereoselectivity in the reactions
在光学活性双环供体-受体环丙烷(例如(1S,5R,6S)-6-芳基-1-甲氧基羰基-3-氧杂双环[3, 1,0]己-2-酮继续以高至高收率和优异的dr和ee生成具有三个连续手性中心的反式-α,β-二取代γ-丁内酯。将醇的负载量增加至两个当量可改善带有烷氧基取代的芳基的双环内酯反应中的非对映选择性。根据结果,我们提出了包括S N在内的OHM反应的合理机制。2'-样亲核试剂的添加。本方法可以为包括各种天然木脂体内酯在内的反式-α,β-二取代的γ-丁内酯的不对称合成提供新途径。