Synthesis of Functionalized 2-Alkylidenetetrahydrofurans by Cyclization of 1,3-Bis(trimethylsilyloxy)-1,3-butadienes with Epoxides
作者:Peter Langer、Holger Armbrust、Tobias Eckardt、Jörg Magull
DOI:10.1002/1521-3765(20020315)8:6<1443::aid-chem1443>3.0.co;2-0
日期:2002.3.15
7-oxabicyclo[4.3.0]nonanes. The cyclization of dienes with functionalized epoxides containing base-labile groups proceeds with good chemoselectivity. In all reactions, good regio- and E diastereoselectivities are observed. Based on the stereoselectivities observed for reactions of 1,2-disubstituted epoxides, a working hypothesis for the mechanism of the reaction is suggested.
Lewis酸介导的1,3-双(三甲基甲硅烷氧基)-1,3-丁二烯,1,3-二羰基二价电子中性当量的环氧化物环化反应导致形成具有多种取代方式和功能的2-亚烷基四氢呋喃组。这包括2,3'-二呋喃基亚烷基和7-氧杂双环[4.3.0]壬烷的合成。二烯与含有碱不稳定基团的官能化环氧化物的环化反应具有良好的化学选择性。在所有反应中,均观察到良好的区域和E非对映选择性。基于观察到的1,2-二取代环氧化物反应的立体选择性,提出了反应机理的可行假设。