General stereoselective synthesis of (E)-exo-alkylidene tetrahydrofurans via base-mediated cyclization of hydroxyl propargylic sulfones
作者:Wei-Min Dai、Mavis Yuk Ha Lee
DOI:10.1016/s0040-4020(98)00730-3
日期:1998.10
The base-promoted cyclization of a number of phenyl propargylic sulfones possessing a β-hydroxyl group afforded 5-substituted (E)-2-[(benzenesulfonyl)methylene]tetrahydrofurans 3 in >80% yield. The phenyl allenicsulfone, formed by isomerization of the phenyl propargylic sulfone under the basic conditions, is attacked by the internal alkoxide to give an allylic anion which undergoes protonation to