A Samarium(II)-mediated, stereoselective cyclization for the synthesis of azaspirocycles.
Unsaturated keto-lactams undergo sequential conjugate reduction-aldol cyclization on treatment with SmI 2 to give syn-spirocyclic pyrrolidinones and piperidinones containing vicinal, fully substituted stereocenters with complete diastereocontrol. The substituent on nitrogen and the lactam ring size have a marked impact on the efficiency of the spirocyclization.
Guazzelli
Giuditta
G
School of Chemistry, University of Manchester, Oxford Road, Manchester, M13 9PL, UK. david.j.procter@manchester.ac.uk
Duffy
Lorna A
LA
Procter
David J
DJ