(+-)-2-Butanol → Chromanone

Participants

Reaction Conditions

Reaction Steps

A solution of protected hydroxyarylketone (1.0 equiv), 4-iodobenzaldehyde (1.0 equiv), piperidine (0.35 equiv), and DBU (0.35 equiv) in s-butanol (1.0 M) was heated at reflux. Using a Dean-Stark trap, half of the solvent was removed over 30-40 min, and the reaction was kept at reflux without further concentration for additional 4-8 h. The reaction mixture was cooled to 90° C., i-propanol (0.7-1.0 fold of s-butanol v/v) was added, and the reaction was allowed to cool to room temperature. Any large pieces of material were broken down with a spatula, and the suspension was stirred overnight (Note #1 & 2). The precipitate was collected by filtration to give the corresponding chromanone.

Provenance & Evidence