Concomitant epoxide deoxygenation and deacetylation of glycidyl acetates induced by telluride ion

Treatment of glycidyl acetates with telluride ion (Te 2- ) produced by reduction of elemental Te with LiEt 3 BH yields allylic alcohols by loss of the epoxide oxygen atom and the acetyl group from the ester. If the glycidyl acetate is disubstituted at C-3, a rearrangement to an isomeric allylic alcohol competes with the deoxygenation-deacetylation. Triethylborane, a byproduct in the reduction of Te, is believed to play an important role as a Lewis acid since when it is absent or removed by addition of fluoride ion the reaction is extremely slow