The synthesis of tedanalactam was to begin with the reaction of the diazoacetamide 1a with the TBS protected 3-hydroxypropanal 2a. When these two reagents were treated to the catalyst prepared as had been previously optimized for the epoxidation of aldehydes, 1 none of the cisepoxide 11 was observed and only 10% conversion was observed under the standard conditions (Scheme 2). This is in contrast to the reaction of diazoacetamide 1a with nonanal 2b which gave the epoxide 12 in 93% yield and >99% ee under the same conditions. The presence of DMSO in these reactions doesn't have a great deal of influence typically giving slightly faster reactions and in some cases giving slightly higher asymmetric inductions. A repeat of the reaction of 1a and 2a without using DMSO in the preparation of the catalyst gave a 12% yield of 11 with 15% conversion. This is again in contrast to the reaction of nonanal which gave 12 in 82% yield with >99% ee without DMSO.