Stereoselective synthesis of contiguous THF-THF and THF-THP units via PdII-catalyzed tandem reaction with 1,3-chirality transfer

The PdII-catalyzed tandem cyclization of chiral allylic alcohols possessing an internal epoxide and a terminal alcohol provided a contiguous THF-THP and THF-THP ring units stereospecifically. The cyclizations take place via a 5-exo-tet-5-exo-trig mode, however, the cyclization of methyl substituted epoxy diols proceeded via 6-endo-tet-6-exo-trig fashion in a part to construct the oxygen-fused THP-THP ring. The different reaction rates of precursors, which are different stereochemistry at allylic alcohol have been elucidated.