Stereoselective synthesis of boronolide and 5-epi-boronolide was achieved from d-(-)-tartaric acid. The key step involves the reduction of a keto Weinreb amide for the synthesis of boronolide, and a single pot construction of a diketone from the bis-Weinreb amide of tartaric acid and subsequent reduction with L-Selectride for 5-epi-boronolide. © 2006 Elsevier Ltd. All rights reserved.