Stereoselective synthesis of tetrahydropyran-tetrahydrofuran (THP-THF) core of (+)-muconin via Prins cyclization

A stereoselective synthesis of tetrahydropyran-tetrahydrofuran (THP-THF) core 2 of (+)-muconin (1) has been achieved using Prins cyclization as a key step to construct tetrahydropyran moiety. Other important transformations such as Wittig olefination, Sharpless epoxidation, regio-, and stereoselective exo-cyclization of the epoxy alcohol, titanocene induced regioselective deoxygenation of 2,3-epoxy alcohol, Grignard reaction, and Barton-McCombie reaction are successfully employed to accomplish the synthesis of THP-THF core 2.