A catalytic method for the preparation of a series of fatty acid derived biocarbonates has been developed using a binary Al-complex/PPNCl catalyst. This catalyst system allows conversion of fatty acid derived epoxides under comparatively mild reaction conditions (70–85 °C, 10 bar) while maintaining high levels of diastereospecificity with cis/trans ratios of up to 97 : 3 in the products. The comparative catalysis data obtained for the reactions catalysed only by the nucleophilic halide based components show that the presence of the Al-complex is crucial for the retention of the original stereochemistry.