Stereoselective Synthesis of 2,4,5-Trisubstituted Tetrahydropyrans Using an Intramolecular Allylation Strategy
作者:Peter J. Jervis、Benson M. Kariuki、Liam R. Cox
DOI:10.1021/ol061957v
日期:2006.9.1
A highly stereoselective route to 2,4,5-trisubstituted tetrahydropyrans is reported. The key step employs an intramolecular allylation of a (Z)-allylsilane onto an aldehyde under Bronsted acid activation. Complete 1,4-stereoinduction accounts for the formation of only two out of the possible four THP products. The level of 1,3-stereoinduction is optimal when the reaction is carried out in an apolar
报道了对2,4,5-三取代的四氢吡喃具有高度立体选择性的途径。关键步骤是在布朗斯台德酸活化下,将(Z)-烯丙基硅烷分子内烯丙基化到醛上。完整的1,4-立体诱导仅占可能的四种THP产品中的两种。当反应在非极性溶剂中进行时,1,3立体诱导的水平最佳,这与静电是控制立体选择性这一方面的关键。