Enantioselective Synthesis of 6,6-Disubstituted Pentafulvenes Containing a Chiral Pendant Hydroxy Group
作者:Ryan Nouch、Melchior Cini、Marc Magre、Mohammed Abid、Montserrat Diéguez、Oscar Pàmies、Simon Woodward、William Lewis
DOI:10.1002/chem.201704247
日期:2017.12.6
Simple enantioselective synthesis of 6,6‐disubstituted pentafulvenes bearing chiral pendant hydroxy groups are attained by cascade reactivity using commercially available proline‐based organocatalysts. Condensation of cyclopentadiene with the acetyl function of a 1,2‐formylacetophenone, followed by cyclization of a resulting fulvene‐stabilized carbanion with the formyl group, generates bicyclic chiral
使用市售的脯氨酸基有机催化剂,通过级联反应,可以轻松合成带有手性侧链羟基的6,6-二取代的五烯丙基戊烯的简单对映选择性合成。缩合环戊二烯与1,2-甲酰基苯乙酮的乙酰基官能团,然后环化生成的带有甲酰基的富烯稳定的碳负离子,生成双环手性醇,其er初始值高达94:6。结晶后会得到异常丰富的醇对映体富集-即使是外消旋的样品也会自发消旋。这使得能够快速获得对映体和非对映体纯的新的取代的环戊二烯家族。