Terminal Cyclopropylsilyl Alcohols as Useful Key Units to Access 2,3,4,6-Tetrasubstituted Tetrahydropyran Scaffolds by Stereocontrolled Prins Cyclization.

In this study, the use of terminal cyclopropylsilyl alcohols in Prins cyclization is reported as a very efficient methodology for the preparation of polysubstituted tetrahydropyrans, in which three new stereogenic centers have been created in a single pot. The reaction is general for a wide variety of aldehydes (alkylic, vinylic, aromatic, or dialdehydes), different types of alcohols, and halogenation agents providing high yields and excellent diastereoselectivity 2,3,4,6-tetrasubstituted tetrahydropyranyl frameworks. Interestingly, diastereomeric alcohols provide the same tetrahydropyranyl derivatives, showing that the reaction mechanism proceeds through common intermediates.