Acetal−Vinyl Sulfide Cyclization on Sugar Substrates: Effect of Structure and Substituent
作者:Pradip K. Sasmal、Martin E. Maier
DOI:10.1021/jo026163i
日期:2003.2.1
vinyl or propenyl side chain. Extension of the alkene by a Suzuki cross-coupling reaction with 1-bromo-1-(phenylthio)ethene gave thioenol ethers as the cyclization substrates. The treatment of these substrates with BF(3).Et(2)O in tert-butylmethyl ether below 0 degrees C induced cyclization to optically active bicyclic ethers. If the cyclizations are carried out in toluene as the solvent, the isomerization
一系列2-脱氧呋喃糖苷和-吡喃糖苷衍生物被制成带有乙烯基或丙烯基侧链的衍生物。通过与1-溴-1-(苯硫基)乙烯的铃木(Suzuki)交叉偶联反应进行烯烃的延伸,得到硫代烯醇醚作为环化底物。在低于0摄氏度的叔丁基甲基醚中用BF(3).Et(2)O处理这些底物可诱导环化为光学活性双环醚。如果环化是在甲苯作为溶剂中进行的,则末端硫烯醇醚异构化为内部的硫烯醇醚可以在环化之前进行。空间和电子因素可能会阻碍环化反应。双环醚的开放可以用酮53向环辛烯酮54的碱诱导转化来说明。