A formal synthesis of (+)-cassiol using (1S,2S)-2-amino-1-(4-nitrophenyl)-1,3-propanediol as chiral auxiliary is reported. The quaternary chiral center in the molecule was constructed by sequential alkylation of a bicyclic lactam (prepared from the aforementioned auxiliary and 5-oxo-heptanoic acid) with methyl iodide and benzyloxymethyl chloride. A formal synthesis of (+) - cassiol using (1S, 2S) -2-amino-1- (4-nitrophenyl) -1,3-propanediol as a chiral auxiliary is reported. The quaternary chiral center in the molecule was constructed by sequential alkylation of a bicyclic lactam (prepared from the Ancillary and 5-oxo-heptanoic acid) with methyl iodide and benzyloxymethyl chloride.