one-pot synthesis of some new α-bromoketals and acetals via 1,8-diazabicyclo[5.4.0] undec-7-ene-hydrobromideperbromide

Α-bromoketals and acetals are important synthetic precursors in organic synthesis. in this work, some new α-bromoketals are synthesized by the reaction of aryl methyl ketones with diols in the presence of 1,8-diazabicyclo[5.4.0] undec-7-ene (dbu) hydrobromide-perbromide in good isolated yields. the latter compound converts aldehydes to acetals and serves as a new and efficient reagent for the synthesis of acetals. comparative studies of the preparation of α-bromoketal and acetals using some reported methods versus the present method show that dbuh-br3 is one of the most efficient reagents for the preparation of these compounds. conversion of carbonyl compounds to corresponding α-bromoketals and acetals in the presence of dbuh-br3 under microwave irradiation is also described.