The reversal in enantioselectivity also extends to the series of aliphatic aldehydes shown in Table . The unbranched aldehyde butanal can be transformed to epoxide 36a in 84% yield and 95% ee and to epoxide 36b in 79% yield and 94% ee. The secondary carboxaldehyde 31 can be epoxidized to give 37a in 81% yield and 94% ee. The epoxidation of the tertiary carboxaldehyde 32 by the VAPOL-Al catalyst gives the epoxide 38a in 99% ee, but in only 50% yield. The substrate scope was extended to tbutyldimethylsiloxy substituted aldehydes 33 and 34 which have one less and one more methylene between the siloxy group and the aldehyde function than aldehyde 2a, respectively. While the latter gives epoxide 40a in 88% yield and 92% ee, the former is not a good substrate, giving the epoxide 39 at best in 86% yield but only 54% ee. The aldehyde 35 was also examined in an effort to see what other functionality might be tolerated in this reaction. Here the ester group is well tolerated giving the epoxide 41a in 74% yield and 96% ee with the VAPOL-Al catalyst. It is interesting to note that the VANOL-B catalyst (10 mol%) gives the enantiomer of the same epoxide in 99% yield and 95% ee under the conditions shown in Scheme 2 with DMSO and 80% yield and 91% ee without DMSO (last two entries in Table ). It is to be noted that while the VAPOL-Al catalyst gave better asymmetric induction (~10% ee) than the VANOL-Al catalyst for the epoxidation of the aldehyde 2a, the epoxidation of benzaldehyde with the two catalysts gives similar results (95% and 96% ee, See Table -I in Supporting Information).