A tellurium-triggered domino reaction for the synthesis of a 1-substituted-3-vinyl-1,3-dihydroisobenzofuran

Telluride ion reacts with an oxiranemethanol toluenesulfonate in toluene under phase-transfer conditions to give an allylic alkoxide anion that is trapped by addition to an adjacent α,β-unsaturated ester to yield a furan derivative. Use of a non-racemic oxiranemethanol tosylate gives two furan diastereomers in a ratio of 56:44.