| Summary: | The syntheses of novel 1-acyloxyindole compounds <b>1</b> and the investigations on reaction pathways are presented. Nitro ketoester substrate <b>2</b>, obtained in a two-step synthetic process, underwent reduction, intramolecular addition, nucleophilic 1,5-addition, and acylation to afford 1-acyloxyindoles <b>1</b> in one pot. Based on the systematic studies, we established the optimized reaction conditions for <b>1</b> focusing on the final acylation step of the intermediate 1-hydroxyindole <b>8</b>. With the optimized conditions, we succeeded in synthesizing 21 examples of new 1-acyloxyindole derivatives <b>1</b> in modest yields (Y = 24 − 35%). Among the 1-acyloxyindole compounds, 1-acetoxyindole compounds <b>1x</b> were generally unstable, and their yields were relatively lower than the other 1-acyloxyindoles. We expect that a bulkier alkyl or aromatic group on R<sup>2</sup> could stabilize the 1-acyloxyindole compounds. Significantly, one-pot reactions of a four-step sequence successfully generated compounds <b>1</b> that are all new and might be difficult to be synthesized otherwise.
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