One-Pot Synthesis of Some New α-Bromoketals and Acetals via 1,8-Diazabicyclo[5.4.0] Undec-7-ene-Hydrobromide-Perbromide

Abstract

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.

Keywords

• 1,8-diazabicyclo[5.4.0] undec-7-ene (dbu) hydrobromide-perbromide
• aryl methyl ketones
• α-bromoketals
• acetals
• microwave irradiation