Reaction of benzoxasilocines with aromatic aldehydes: Synthesis of homopterocarpans

Abstract

Condensation of 2H-benzo[g][1,2]oxasilocines with aromatic aldehydes in the presence of boron trifluoride affords mixtures of cis/trans 2-phenyl-3-vinylchromans with moderate yields. These can be transformed into homopterocarpans, a synthetic group of substances homologous to the natural isoflavonoid pterocarpans. © 2007 Álvarez-Corral et al; licensee Beilstein Institut.