AbstractAn extremophilic challenge: Stereospecific condensation of a fully functionalized ketal aldehyde and a 2,6‐dihydroxybenzoic acid is the key step in the synthesis of (−)‐berkelic acid confirming Fürstner's reassignment of the stereochemistry at C18 and C19, establishing the absolute stereochemistry, and tentatively assigning the stereochemistry at C22.magnified image