Expanding the silyl-Prins toolbox: selective access to C4-quaternary stereocenters in tetrahydropyrans using internal cyclopropylsilyl alcohols

Abstract

Our ongoing research into silyl-Prins cyclizations has now provided a promising solution for the stereoselective synthesis of tetrahydropyrans bearing quaternary centers at C4. Building on previous success with terminal cyclopropylsilyl alcohols, we now demonstrate that internal cyclopropylsilyl alcohols can also be effectively employed to construct highly substituted tetrahydropyrans. This new approach delivers products featuring both a quaternary center at C4 and a tertiary center at C6 with excellent stereocontrol. These findings not only broaden the scope of silyl-Prins cyclization but also establish a general and efficient strategy for accessing complex oxacyclic architectures with precise stereochemical outcomes.