No abstract

Readily available 4-formyloxyazetidinone was enantioselectively transformed into 3,4-benzo-2-hydroxy-5-oxacephams and 4-phenyloxyazetidinones upon treatment with 0.1 equiv of the cinchona alkaloid in toluene via intermolecular nucleophilic trapping of N-acyliminium intermediate by the hydroxyl moiety of phenols or o-hydroxybenzaldehydes. Additionally, the absolute configuration of title compounds was established by CD spectroscopy.

An improved synthetic protocol is developed for the highly regio‐ and diastereoselective synthesis of spiroisoxazoles (IV) via a domino double nucleophilic addition—cyclization—alcoholic sequence.

Readily available 4-formyloxyazetidinone was enantioselectively transformed into 4-substituted azetidinones upon treatment with 0.1 equiv. of the cinchona alkaloid (quinidine) in toluene via intermolecular nucleophilic trapping of the N-acylimine intermediate by mercapto-, or hydroxymoieties of thiophenols, thiols, phenols and alcohols. Additionally, biological activity tests were performed on the newly synthesized β-lactams.

Azetidine derivatives R 0045 Chiral Base Catalyzed Enantioselective Synthesis of 4-Aryloxyazetidinones and 3,4-Benzo-5-oxacephams. -(KOZIOL, A.; FURMAN, B.; FRELEK, J.; WOZNICA, M.; ALTIERI, E.; CHMIELEWSKI*, M.; J. Org. Chem. 74 (2009) 15, 5687-5690; Inst. Org. Chem., Pol. Acad. Sci., PL-01-224 Warsaw, Pol.; Eng.) -Jannicke 51-126