Cycloadditions. 41. Conversion of unsaturated alcohols into functionalized tetrahydrofurans and tetrahydropyrans via nitrile oxide dipolar cycloadditions
Formation of functionalized cyclic ethers by intramolecular nitrile oxide cycloadditions
作者:Albert Padwa、Ugo Chiacchio、Dennis C. Dean、Allen M. Schoffstall、Alfred Hassner、K.S.K. Murthy
DOI:10.1016/s0040-4039(00)80447-5
日期:1988.1
The reaction of O-trimethylsilyl α-bromo aldoximes with unsaturated alcohols produces oximino ethers which can be readily oxidized with sodium hypochlorite. The transient nitrile oxide intermediate formed undergoes spontaneous cyclization affording fused isoxazolines. MM2 calculations help rationalize the observed stereoselectivity.