Synthesis of Reactive Intermediates for Natural Cyclopentane Derivatives from (−)‐Quinic Acid: Preparation of 11α‐hydroxy‐13‐oxaprostanoic acid

We describe a flexible, stereocontrolled synthesis of enantiomerically pure substituted cyclopentenes and cyclopentanes - including 11α-hydroxy-13-oxaprostanoic acid 20 - (−)-quinic acid via an acyclic precursor 6 by an intramolecular aldolisation-dehydration reaction.