Stereochemical Prins cyclization: electronic versus steric effects on the synthesis of 2,4,6-trisubstituted tetrahydropyran rings

A convenient approach towards the synthesis of both syn- and anti-2,4,6-chlorotetrahydropyrans has been developed. The electronic and steric influences on the stereochemistry of the Prins cyclized products were investigated based on the substituents of the homoallylic alcohol.