Results Hydroformylation of vinyl acetate was carried out in the presence of rhodium catalysts complexed with a series of DIOP-type ligands at various ligand-to-rhodium ratios and under a variety of pressure and temperature conditions. In general, catalyst complexes were prepared in situ from Rh (C0D) acac and the desired DIOP analogue although in the case of DIOP itself and DIPHOL discreet rhodium complexes were prepared ...