An Approach to the Stereoselective Synthesis of syn - and anti -1,3-Diol Derivatives. Retention of Configuration in the Mitsunobu Reaction

The Mitsunobu reaction typically proceeds with inversion of configuration at the hydroxyl center. However, with a series of hindered alcohols, the intramolecular version of the Mitsunobu reaction afforded exclusively the product of retention of configuration. A mechanistic rationale for this observation is discussed, wherein this atypical stereochemical outcome is attributed to steric congestion at the reaction center.