Diastereoselective access to chiral non‐racemic [1,3]oxazolo‐[2,3‐a]isoindol‐5‐one ring systems viaO‐cationic cyclization

Abstract

Dedicated to Professor Jean Morel for his retirementThe title compounds 4 have been prepared from suitable β−amino-alcohol 2 and phthalic anhydride (5) in a three-step sequence in moderate to good yields (58-94%). The key step of this methodology is based on an intramolecular O-cationic cyclization involving N-acyliminium species. The high levels of the observed chemoselectivity during the intermolecular or intramolecular cyclization were also discussed.