Stereoselective Aldol-Type Cyclization Reaction Mediated by Dibutylboron Triflate/Diisopropylethylamine
作者:Sanjib Das、Lian-Sheng Li、Subhash C. Sinha
DOI:10.1021/ol036229b
日期:2004.1.1
[reaction: see text] Dibutylboron triflate/diisopropylethylamine mediated aldol-type cyclization provides an expedient route for the stereoselective synthesis of cyclic ethers in a single step. The method is highly efficient for the stereoselective synthesis of 4-cis-tetrahydropyranones. The reaction is proposed to proceed via an S(N)1-type mechanism through a chair-like transition state, in which
[反应:见正文]三氟甲磺酸二丁基硼/二异丙基乙胺介导的醇醛型环化为一步立体异构合成环醚提供了一条方便的途径。该方法对于4-顺式-四氢吡喃酮的立体选择性合成是高效的。提出该反应通过S(N)1型机理通过椅子状过渡态进行,其中两个取代基均占据赤道位置。