An alternative scalable process for the synthesis of the key intermediate of omarigliptin is described. The asymmetric synthesis relies on the initial diastereoselective alkylation and subsequent aluminum-catalyzed substrate-controlled Meerwein–Ponndorf–Verley reduction. A highly regioselective 5-exo-dig iodocyclization followed to afford 11b, which was then subjected to ring-opening cycloetherification to give product 1 with >99:1 dr and >99% ee in 31.2% overall yield in nine steps. This synthetic strategy has been successfully applied for multikilogram scale production.