A Symmetry‐Based Synthesis of the Heterobicyclic Core of the Zaragozic Acids/Squalestatins

The pseudo C2‐symmetrical diketone 22 was efficiently constructed from furan‐3,4‐dimethanol (7) using a two‐directional route featuring a double asymmetric dihydroxylation. Acidic hydrolysis of the cyclopentylidene acetals of 22 triggered a selective cyclization of the resulting hexaol diketone to generate the 2,8‐dioxabicyclo[3.2.1]octane core of the zaragozic acids/squalestatins. Chemoselective oxidative cleavage of a superfluous two‐carbon appendage and further functional group manipulations yielded the enantiomerically pure triester 30, which offers itself as a general heterobicyclic building block for naturally occurring zaragozic acids/squalestatins and unnatural analogues.