Based on our early observation of enantioselectivity with C1, we wondered if alternate carbohydrate thiol catalysts may provide enhancement in er (Table , entries 7-9). We synthesized C7 with the hypothesis that utilizing a bulkier protecting group on the sugar backbone may lead to increased enantioinduction; however, we observed no change in er (Table ). Utilizing a galactose backbone (C8) instead resulted in a minor erosion of er (Table , entry 8). Finally, the structurally dissimilar furanose catalyst C9 provided slightly increased enantioinduction, but with a reversal of observed selectivity (Table , entry 9). Given the similarity of results, we decided to continue forward with C1 for method development based on its commercial availability and ease of handling.