Chemoselective acylation of some oxidofunctionalised organolithium compounds

Once oxidofunctionalised organolithium compounds (easily prepared by reductive ring opening of isochroman and phthalan by DTBB-catalysed lithiation) were transmetallated with ZnBr2/CuCN·2LiCl and reacted successively with a carboxylic acid anhydride and an acyl chloride in THF at 0°C, the corresponding differently acylated compounds were obtained after hydrolysis with water. The anhydride performed the O-acylation exclusively and the acyl chloride carried out the C-acylation.