Trost Barry M, Crawley Matthew L, Lee Chul Bom
Department of Chemistry, Stanford University, Stanford, CA 94305-5080, USA.
Chemistry. 2006 Mar 1;12(8):2171-87. doi: 10.1002/chem.200500919.
Palladium-catalyzed asymmetric allylic alkylations (AAA) to form "chiral aldehyde" equivalents were investigated. Alpha-acetoxysulfones were formed in high enantiomeric excess as single regioisomers in AAA reactions of allylic geminal dicarboxylates with sodium benzenesulfinate. The directing ability of this novel functional group was highlighted by a series of dihydroxylations, affording syn diols exclusively anti to the acetoxy sulfone as single diastereomers in excellent yields. This is the first example of an asymmetric dihydroxylation protocol that gives the equivalent of reaction with a simple enal. The synthetic value of this process was exemplified by subsequent transformations of the diols including the development of a one-pot dihydroxylation-deprotective acyl migration protocol to give differentially protected 1,2-diols.
研究了钯催化的不对称烯丙基烷基化反应（AAA）以形成“手性醛”等价物。在烯丙基偕二羧酸酯与苯亚磺酸钠的AAA反应中，α-乙酰氧基砜以单一区域异构体的形式以高对映体过量生成。一系列双羟基化反应突出了这种新型官能团的导向能力，以优异的产率提供了仅与乙酰氧基砜呈反式的顺式二醇作为单一非对映体。这是不对称双羟基化方案的第一个例子，该方案相当于与简单烯醛的反应。二醇的后续转化举例说明了该过程的合成价值，包括开发一锅法双羟基化-脱保护酰基迁移方案以得到差异保护的1,2-二醇。
