Diastereoselective Addition Reactions of Furyl Aldehydes Using Chiral Boronates as Auxiliary: Application to the Enantioselective Synthesis of 2,3-Disubstituted Furyl Alcohols
作者:Kin-Fai Chan、Henry N. C. Wong
DOI:10.1021/ol010196n
日期:2001.12.1
[reaction: see text] The addition reactions of various nucleophiles to a furyl aldehyde bearing a chiral boronate at the C-3 position furnished chromatographically separable diastereomers. The R diastereoselection was more favorable when no additive was added. Surprisingly, when lithium alkoxides were selected as additives, the S diastereoselection is superior instead. Further transformation of C-B
[反应:见正文]各种亲核试剂与C-3位置带有手性硼酸酯的呋喃醛的加成反应提供了色谱上可分离的非对映异构体。当不添加添加剂时,R非对映异构更有利。令人惊讶地,当锂醇盐被选作添加剂时,S diastereoselection优越代替。通过使用标准的Suzuki偶联条件,将CB键进一步转化为CC键,得到旋光的2,3-二取代的呋喃醇。