A tandem olefin migration and Prins cyclization using Cu(OTf)2-bisphosphine complexes: an improved synthesis of functionalized tetrahydropyrans

In situ-generated (bis-DPPMB)-Cu(OTf)2 complex has been examined to catalyze a tandem olefin migration and Prins cyclization of an alkenol with various aldehydes. The reaction proceeded with electron-rich aromatic aldehydes at room temperature and provided functionalized tetrahydropyrans in good yields. An efficient synthesis of the bis-DPPMB ligand has also been described.