Selectivity on the reaction of vinylic tellurides with butyllithium in the presence of carbonyl compounds

Abstract

The treatment of isomeric vinylic tellurides 5–7 with butyllithium in THF at −78 °C in the presence of a carbonyl compound such as benzaldehyde or cyclohexanone was studied. High selectivity of the attack at the tellurium atom was observed. In most cases, the corresponding allylic alcohol was obtained as the only (or major) product instead of the alcohols derived by the 1,2 addition of BuLi at the carbonyl compound. Similar results were obtained using the ketenetelluroacetal 14 instead of the vinylic monotellurides.