Stereoselective Synthesis of cis ‐Fused Perhydrofuro[2,3‐ b ]furan Derivatives from Sugar‐Derived Allyl Vinyl Ethers

A stereoselective methodology has been developed for the construction of cis ‐fused perhydrofuro[2,3‐ b ]furans, via 3‐ C ‐branched glycal derivatives, involving Claisen rearrangement of sugar‐derived allyl vinyl ethers, followed by a one‐pot ozonolysis and acid‐mediated acetalization. The methodology was used for the stereoselective synthesis of the P 2 ligand in the recently FDA approved HIV protease inhibitor darunavir (Prezista). The methodology was also successfully used for the synthesis of cis ‐fused perhydro‐5‐oxofuro[2,3‐ b ]furan derivatives.