Enantioselective Ammonium Ylide Mediated One‐Pot Synthesis of Highly Substituted
<i>γ</i>
‐Butyrolactones
作者:Till Drennhaus、Laura Öhler、Saveh Djalali、Svenja Höfmann、Clemens Müller、Jörg Pietruszka、Dennis Worgull
DOI:10.1002/adsc.202000039
日期:2020.6.15
diastereoselectivities (>95:5) via a DABCO‐mediated [2+1] annulation. Utilization of enantiomerically pure cinchona alkaloid derivatives enables the first asymmetric ammonium ylide mediated method to provide (3R , 4R )‐β,γ ‐disubstituted and (2R , 3R, 4R )‐α,β,γ ‐trisubstituted γ ‐butyrolactones in moderate to good yields with up to very good enantiomeric ratios (97:3). The scalability of the transformation
对铵内盐介导的接入反式β,γ双取代的,全反式- α,β,γ三取代,和α,α,β,γ -tetrasubstituted γ丁内酯轴承各种各样的功能开发。从广为人知的亚苄基Meldrum酸衍生物和α-溴代羰基化合物开始,通过DABCO介导的[2 + 1]环化法获得的γ-丁内酯的收率在32-99%之间,具有极好的非对映选择性(> 95:5)。对映体纯金鸡纳生物碱衍生物的使用使第一个不对称的叶立铵铵介导的方法能够提供(3 R,4R)-β,γ-二取代和(2 R,3 R, 4 R)-α,β,γ-三取代γ-丁内酯,产率中等至良好,对映体比例非常高(97:3)。在确定绝对配置时,证明了转换的可伸缩性。