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

Dedicated to Professor Jean Morel for his retirement The 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.