Achieving High Selectivity and Facile Displacement with a New Thiol Auxiliary for Boron-Mediated Aldol Reactions
作者:Sandra Fanjul、Alison N. Hulme、John W. White
DOI:10.1021/ol0614774
日期:2006.9
Synthesis of a new thiol auxiliary (1) is readily achieved (in five or six steps, >74% overall yield from norephedrine) and is shown to give high diastereoselectivity in boron-mediated anti-aldol reactions with a range of aldehydes. This new thiol auxiliary may be directly displaced by a range of nucleophiles under very mild conditions, to give the corresponding phosphonate esters, alcohols, acids
新的硫醇助剂(1)的合成很容易实现(通过五步或六步,从去氧麻黄碱中获得的总收率> 74%),并且在与多种醛的硼介导的抗醛醇缩合反应中显示出很高的非对映选择性。这种新的硫醇助剂可以在非常温和的条件下被一系列亲核试剂直接置换,得到相应的膦酸酯,醇,酸,SNAC硫代酯和甲酯。