Stereospecific annulation of hydroxy vinyl ethers. Synthetic application to polyfunctionalized cyclic compounds

Article abstract of DOI:10.1016/0040-4020(96)00253-0

Stereospecific annulation of hydroxy vinyl ethers in the presence of triflic anhydride and tertiary amines and its synthetic application are described. Each 1-hydroxy-2-oxabicyclo(n.4.0)alkane, 2-oxabicyclo(n.4.0)alk-1(6)-ene and 2-oxabicyclo(n.4.0)alk-1(6+n)-ene is stereoselectivity synthesized from the same hydroxy vinyl ether depending on the choice of the reaction conditions (temperature, solvent and tertiary amine). These compounds lead to polyfunctionalized cyclic compounds and some natural product. We propose that this annulation reaction proceeds through a pure S(N)2-like mechanism.