1376574-92-3Relevant academic research and scientific papers
Synthesis of spirocyclopropyl γ-lactams by tandem intramolecular azetidine ring-opening/closing cascade reaction: Synthetic and mechanistic aspects
Nocquet, Pierre-Antoine,Hazelard, Damien,Compain, Philippe
, p. 4117 - 4128 (2012)
The scope and limitations of a novel intramolecular azetidine ring-opening/closing cascade reaction affording spirocyclopropyl γ-lactams from azetidines in high regio- and stereoselectivity is reported. The key step of the process is a SN2-type ring-opening of TMSOTf-activated azetidine rings by silyl ketene acetals generated by treatment with TMSOTf and TEA. This study is a very rare example of nucleophilic ring-opening of azetidines that does not require formation of quaternary azetidinium salts by N-alkylation or the use of N-electron-withdrawing groups. Application of this process to 2-azetidinone system led to a complete change in reactivity and provide 6-aza-bicyclo[3.2.0]heptane derivatives via an unprecedented Mukaiyama aldol-like reaction involving an ester acceptor and a silyl imidate.
