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.