Rapid and Efficient Protocol for the Synthesis of 4-Chlorotetrahydropyrans Using Niobium(V) Chloride
作者:J. S. Yadav、B. V. Reddy、Manoj Kumar Gupta、Swapan Kumar Biswas
DOI:10.1055/s-2004-831220
日期:——
Aldehydes undergo a rapid coupling with 3-buten-1-ol utilizing 20 mol% of niobium(V) chloride to afford 4-chlorotetrahydropyran derivatives under extremely mild conditions within short reaction times in excellent yields with high selectivity. The similar halogenated tetrahydropyrans are also obtained using gallium(III) halides.
An Efficient Prins Cyclization for Stereoselective Synthesis of Tetrahydropyran from Imines and Homoallyl Alcohols
作者:Congrong Liu、Daojuan Cheng、Fulai Yang
DOI:10.1002/cjoc.201400450
日期:2014.11
An unprecedented protocol has been developed for the efficientsynthesis of substituted tetrahydropyrans via a bismuth‐promoted Prinscyclization of imines with homoallylalcohols. In the presence of 40 mol% BiCl3, a wide variety of imines react smoothly with homoallylalcohols at room temperature to give the corresponding 4‐chlorotetrahydropyran derivatives in good to excellent yields.